The Chevy Volt Gets 230 mpg? Only if you use bad math.

Here’s a quick bit of obnoxious bad math. I saw this myself in a link to an AP article via, and a reader sent me a link
to the same story via CNN. It’s yet another example of what I call a metric error: that is, the use of a measurement in a way that makes it appear to mean something very different than what it really means.

Here’s the story. Chevy is coming out with a very cool new car, the Volt. It’s
a hybrid with massive batteries. It plugs in to your household electricity when you’re home to charge its batteries. It operates as an electric car until its batteries start to get low, and then it starts running a small gas motor to power a generator. It’s a very cool idea. I’m honestly excited about cars like the volt – and Google helped develop the technology behind it, which biases me even more in its favor. So you’d expect me to be very supportive of the hype around it, right? I wish I could. But GM has decided that the best way to promote it is to use bad math to tell lies to make it look even better than it really is.

Chevy has announced that for city driving, the Volt will get gas mileage of 230 miles per gallon.

That’s nonsense. Pure, utter rubbish.

The trick is that they’re playing with the definition of mileage. In city driving, the Volt is primary an electric car: it’s powered by its batteries which you must recharge every night, not by gasoline. On average, you can drive it for about 40 miles on a full charge before it needs to start using any gasoline.

The “mileage” figure, as it’s presented, is really meaningless – because it’s being presented for a situation in which the gasoline engine almost never runs at all.

They compute it by basically saying: “If I fully charge the car battery every night, how far will I drive the car in typical city commuting conditions before it’s consumed a gallon of gas”.

What if you drive your volt around the city all day? Your mileage will drop to around 50 miles per gallon once you’ve driven more than 40 miles. If you drive your car 100 miles in a day, you’ll consume a bit over a gallon of gas. That’s very impressive. But it’s absolutely not what you’d expect after being told that it
gets 230 miles per gallon.

The method that GM used to produce that mileage figure is
extremely dishonest and completely uninformative. The “real” effective mileage (excluding the cost of charging the car – which will be significant!) varies depending on the length of your commute.

My wife could commute in a Volt, and never put gas in it: her commute is about 12 miles each way – so she’d effectively have
infinite mileage according to GMs method. If I commuted in a volt, I’d get something around 288 miles per gallon. (My commute is 24 miles each direction, leaving me with 8 miles per day running on gas; so about 6 days of my commute would consume a gallon of gas; that’s 288 miles.) If one of my friends, who commutes 45 miles each direction per day, were to commute in a Volt, he’d end up burning a gallon of gas
per day – getting around 90 miles per gallon.

Plug-in hybrids are a new class of car. You can’t
really describe their efficiency compared to a conventional gasoline-powered car using a single familiar figure. You could
present energy efficiency in terms of a unit like
“distance per kilojoule”, but most people won’t have a clue
of what that means. The honest way to describe it is to say “Up to 40 miles without consuming gas, and then 50 miles per gallon”. That’s not
so horribly difficult, now is it?

But it doesn’t sound nearly as impressive as “230 miles per gallon”.

0 thoughts on “The Chevy Volt Gets 230 mpg? Only if you use bad math.

  1. dean

    You expected honesty from marketing? I’m shocked, shocked at the deception 😀
    I noted the same thing this morning when one of our local (Michigan) news shows jumped on this news as a sign the “new” company would be a success.
    I also jumped on the news from yesterday that the new GM is claiming that they are not responsible for cars with mercury switches, and will not participate in the cleanup that GM had been carrying on for years. The part of GM that is in bankruptcy is “studying the issue”.
    From an AP news story:
    General Motors has quit working with a partnership that collects toxic parts from scrapped automobiles, jeopardizing an effort to prevent mercury pollution just as hundreds of thousands of clunkers are headed to recyclers.
    Participants in the environmental program said that the timing of GM’s departure could hurt their work. The government’s “cash-for-clunkers” program will lead to the trade-in and recycling of an estimated 750,000 vehicles, some of which contain mercury switches.
    GM says it is a new company, formed with substantial government aid in the wake of bankruptcy protection, and is not a member of the partnership because it doesn’t make vehicles with mercury switches and is not responsible for the older vehicles. The old company, which is still under bankruptcy court supervision, says it is reviewing agreements involving the former company and declined to comment.
    It’s enlightening to see that even the new GM uses many of the practices of traditional companies. (

  2. Mike Olson

    Thanks for posting this info. It does sound like an exciting development. I’m curious, however, as to how much it will cost to fully charge the car each night. If you’re driving 12 miles to commute everyday, but spend $5 on electricity to do it, it wouldn’t be worth it. Any info?

  3. Eddie Welker

    Good post. I saw the number pass in-front of my eyes this morning through RSS. I paused for a second, and then called BS (not caring enough to determine why). Thanks for giving me the answer.

  4. Mark C. Chu-Carroll

    According to GM, an average charge after a daily commute using the same scenario that produced the 230 mpg would consume about 8 kilowatt hours. The most recent figure I could find for the average cost of a kilowatt-hour for residential electricity users is for June of this year, when it was around 5.7 cents per kwh. So the daily charge-cost for driving somewhat under 40 miles per day on average works out to around 50 cents per day of electricity. Compare that to gasoline, where an average car will consume at least one full gallon of gas for a comparable distance, and the plug-in hybrid really does look great.
    That’s really what bugs me so much about this: an honest presentation of how this car performs is damned impressive. The dishonest presentation of it is completely phony and unrealistic, and will result in people being profoundly disappointed by the real performance of the car. If you understand that the car gets 50mpg, and it doesn’t need any gas until you’ve gone 40 miles, then it’s performance will be really impressive compared to your old gas car. But if you’re expecting to get 300mpg, and you really get an average of 50mpg when you drive it, you’re going to be profoundly disappointed.
    It’s just dumb.

  5. Ronald Prusinski

    I think we have just begun to see the hype as more companies develop alternate energy (fuel cell, hydrogen, clean diesel, etc) vehicals.

  6. Jim Thomerson

    Well, at least they didn’t use (yet) your infinate mileage figure. If charging is usually done at night, it will be during off-peak demand hours. Maybe a good thing.

  7. Brian Kozumplik

    Remember that 230 mpg is an EPA estimate, not a General Motors claim. The stickers on the windows, including this one, are not from the manufacturers, but from EPA mandated test procedures. If you have issues with it, contact your government, not GM.

  8. flargh

    “You expected honesty from marketing”
    If it were just GM trumpeting their mythical 230 mpg figure, I might accept that it’s just marketing ding what it does best. But that number comes from a preliminary report authored by the Environmental Protection Agency (EPA), a government agency that you’d think would have consumer interest and the general education of the public as a priority. Unfortunately not. Therefore, their lousy, marketing-driven calculus leads Chevrolet to trumpet the 230 mpg figure, even though it’s utter horseshit.

  9. Andy Simon

    ” the use of a measurement in a way that makes it appear to mean something very different than what it really means.”
    Welcome to Obama World where everything that is wrong is right and everything that doesn’t make sense does.
    This is the same tactic used to promote everything now days. Find a way to lie to the people in a way that will make them feel good.
    As long as you “Hope” that the car will use very little gas you can count on the “Change” that you want others to see. After all being green isn’t about helping the environment, it is about the image you portray to others so they might think you are doing something to help.

  10. kahunaman

    the problem that GM is trying to combat here is that consumers are trained to look at mpg and not at a more detailed description. unfortunately, i have seen the 50 mpg statistic way more often and that is just as misleading as the 200+ mpg statistic.
    The Volt was designed for urban commuters, the majority of whom drive less than 40 miles per day. your example of a friend who drives 45 miles each way to work is not very apt in this situation since even the EPA quote of 200+ mpg was listed for city driving. That is an awful big city if you can commute 45 miles one way.
    You should lighten up on this claim a little. It accomplishes its task which is to get people talking about the Volt and this new technology. Saying that the Volt will get 50 mpg does the car a disservice by dumping it in with the Prius and other hybrids. For commuters who are going short distances to and from work, it will be vastly superior in efficiency to a Prius.

  11. financial tools

    Mark, thank you for the facts about the Volt, and not only they use bad math, we will never see the Volt in 2010 because they will say then that : “…due to unexpected difficulties, we will postpone the Volt until 2011 and oh,yes ! we need another 20 billion from the USA taxpayers and the key G.M. assets – Asian and Latin American operations – are being sold to the Hedge-Funds represented in the Board of Directors of G.M….. and about the USA Debt and Obligations : that’s for the USA taxpayers to deal with…wonderful,eh ?
    It’s all another lie, it’s just a trick to extort more money and blame the disaster in 2010 to the Obama-Biden Administration, this will make them look like fools, plus the Hedge Funds ( Carlyle and TPG in the G.M. Board and their bankers Goldman Sachs and BlackRock will end-up with the only good G.M. assets ) it’s a total fraud !
    Since G.M. sold the best assets of Hughes to Rupert Murdoch and their advisers and lawyers made 200 million dollars while Congress looked the other way , we know is a lost cause….and they now install a Director of the Board of Exxon-Mobil, Whitaker, as Chairman, so what do we expect ?
    The Union bosses are incompetent and corrupt , the executives are sold to the Oil Lobby and some of the key employees are incompetent, lazy, corrupt or too busy watching the games and the scandal chit-chat to know what’s going on….they were told in 2001-2 to refuse to close down the EV-1 and that Honda and Toyota with hybrids were going to eat them for lunch…and they didn’t do a thing…they went to watch the players —— and the movie stars —–, so we all lost 50 billion dollars , so far, and what a criminal shame the whole deal is !

  12. Dave X

    I like using marginal cents/mile as my mileage metric. With the current price of gas, and my Subaru loaded up with the cartop carrier, I’m paying 12.3c/mile. So a 30-mile round trip costs me $3.69. Cents per mile makes comparisons possible across fuel types, like a plug-in hybrid.
    I also like tracking the marginal costs rather than fully burdened costs, because the depreciation and insurance and the like are sunk costs that don’t depend strongly on how much I drive. Whether or not I forego or combine specific trips depends on the marginal costs of making the trips, not the depreciation of the vehicle.

  13. Blaise Pascal

    What does Obama have to do with this? Or is this just an opportunity to do non-sequitor political Obama-bashing?
    The EPA test procedures which lead to the 200+MPG figure are not new with this administration; they’ve been around for decades, and they’ve been criticized for years as well.

  14. Ktesibios

    So what would be a good way to rate cars like the Volt for energy efficiency- in a way that permits buyers to make valid comparisons between different products?
    If you give a figure for miles per megaJoule, I could convert that to a gasoline equivalent by dividing by the energy content of a gallon of gas (about 1.3 x 108 J, IIRC).
    OTOH, if I’m more interested, as a consumer, in cost to operate, then I need figures on energy drawn from the wall socket in recharging the car, how far I can drive on a fully-charged battery and the price of electricity from my friendly neighborhood electric company.
    The point of EPA-standardized mileage ratings is to permit intelligent comparisons of different cars, even though it might not tell you a great deal about what it’s going to cost an individual owner to drive a given car, much like the FTC rules on audio power amplifier power ratings don’t tell you everything you need to know to predict “how loud it’s gonna be”, but do permit meaningful comparison between competing products.
    Trying to hammer and file the existing mileage-rating measurement standard to fit plug-in hybrids completely defeats the comparative purposes of that particular standard- so we need some better method of rating self-powered vehicles in general for energy costs.
    Anybody got any ideas?

  15. Mark C. Chu-Carroll

    Re #12:
    Even the “marginal cost per mile” is hard to compare using a single number with a plug-in hybrid: the cost per mile has a dramatic changeover point when the gasoline engine kicks in.
    That’s why I said the honest way to describe it is to use two numbers. The cost of the first 40 miles after a charge is the cost of the electricity to charge it; the cost after that is the cost of gasoline to run the generator.
    To get an honest description, you’ve got to use both of those numbers. If you like to talk in terms of mileage, then say “40 miles per charge, then 50 miles per gallon”; if you prefer cost, then something like “1.2 cents per mile the first 40 miles, then 6 cents per mile”.

  16. Righty Loosey

    The announcement I saw wasn’t that the car actually, literally gets 230 mpg, but that ‘using the EPA’s guidelines, which haven’t been finalized yet, this is the expected mileage rating.’ That isn’t deceptive. You and I evidently don’t get our news from the same source.

  17. Gray Gaffer

    1 Hp is approx 750W/sec. So an 8KW hrs charge should allow one to generate about 10 Hp for one hour. Experiential evidence with my trolling motor and a 175 W-hr battery bears this out (no wake runtime in my Coleman canoe is about 1 1/2 hrs. Wind must be

  18. Mark C. Chu-Carroll

    Re #14:
    As I said in the original post, and I’ve said in the comments: you can’t realistically assess the efficiency of a plug-in hybrid with a single number.
    The plug-in hybrid has a changeover point. Its efficiency changes dramatically when the gasoline engine kicks in. You can’t get away from that. So you’ve got to use two numbers: the distance it can go on a charge (and the cost of that charge), and then its gas mileage (or some other equivalent measure.)
    The volt gets 40 miles on a 50 cent electric charge, and then 50 miles per gallon after that. You can’t honestly describe it without both of those figures.

  19. Mark C. Chu-Carroll

    Re #17:
    I didn’t want to get into the comparison between gasoline and electrical generation in this post – that’s a topic for a future post when I have the time.
    It’s an extremely complex issue.
    On one hand: a typical gasoline engine is really pretty efficient. It’s got higher efficiency than a typical petroleum-based electrical generation+transmission system. So if you’re getting your electricity from a gas-powered generator, you’re doing *worse* in terms of petroleum consumption with an electric car.
    Add in the fact that there are some new gasoline engines that are dramatic improvements over traditional engines. There are diesels that get better mileage than hybrids like the volt when it’s running on gasoline.
    On the other hand, cars have really lousy pollution controls. It’s a lot easier and cheaper to put high-quality pollution controls at a centralized power plant than it would be to add pollution mitigation equipment to every single gasoline-powered car.
    The electric also leaves the hope for a better electrical generation system. We don’t have a large scale viable system in place yet, but it’s possible that we’ll develop one.
    So it’s not exactly an easy picture. It’s hard to figure out just what the tradeoffs even *are*, much less where a particular car fits in them. But you’ve got to start somewhere, and at least trying to be honest about it is crucial if we ever want to be able to make meaningful comparisons.

  20. dean

    ” But that number comes from a preliminary report authored by the Environmental Protection Agency (EPA)”
    I heard (several times, actually, most recently this afternoon) that the EPA has not yet given its official stamp to this number. GM has claimed it used the EPA’s testing procedures, and submitted results, but the agency was still evaluating those claims.
    As far as I know that has not changed.

  21. Fock Snooze

    When I was a kid I had a bicycle that got fantastic gas mileage — infinite!
    Oh, wait, division by zero … oops, my bad.

  22. Meeme

    What ever the mileage, it’s significantly more than I currently get with my not-quite-a-clunker. And, it is so cute!!!

  23. Wayne

    One criteria that has to be considered with a electric vehicle is the cost and frequency of battery replacement. This will increase the cost per mile on this vehicle.

  24. Hank Green

    You really should have done a bit more research on this. Some of your claims are valid, but they sounds silly when mixed with mis-information.
    GM did not come up with the 230 MPG number, the EPA did. As the EPA is required by law to do so for every new vehicle, they had little choice.
    The EPA didn’t just use some arbitrary course. They studied american driving habits and made an estimate of how the car will be used when averaged over the entire country.
    Then they used both the amount of gasoline AND the amount of electricity used in those situations to create the 230/100 figure. They didn’t just disregard the electricity, they took the costs and environmental impacts of that electricity into account.
    This doesn’t mean that you’re wrong, of course. There needs to be a better system for dealing with alternative fuels and propulsion for cars. But right now, MPG is what we have and MPG is what consumers understand and what governments regulate. So MPG is what we’re stuck with.
    GM should hardly be blamed for being first to the game and so having to work in a system that isn’t ready for it’s technology. Nor can they be blamed for touting an exciting number created by an unbiased organization that will help sell these new, exciting, and extremely efficient cars.
    I think I will now take this comment and publish it at ecogeek. Lets see if we can get some good discussion going :-).

  25. scrappy

    Meeme, I do hope you like it – because you’re paying for it.
    But if a car company was really coming out with a 230 mpg car next year, do you really think it would be going through bankruptcy this year?
    I wonder how many carbon offsets GM and the gub-ment will need to buy for all the smoke they are producing.

  26. Jeanne

    What is the overall energy cost of charging the battery vs. burning gasoline? Is there some unit of measurement to compare this apple to that orange?
    Yes, I know the electric car doesn’t pollute, but are the batteries full of toxic stuff that will end up in a landfill?
    Can someone tell me why I can’t have turbodiesel (unless I want to buy a VW?).

  27. scrappy

    Hank, how does 367 mpg sound? The Volt is a gas guzzler by comparison.
    “Nissan Leaf = 367 mpg, no tailpipe, and no gas required. Oh yeah, and it’ll be affordable too,” noted the company on its NissanEVs Twitter page. Nissan went on to backup the previous statement adding, “To clarify our previous tweet, the DOE formula estimates 367mpg for Nissan LEAF.”

  28. Dave X

    Re #15, Agree. Both numbers are important for something that switches fuels. Actually, I guess you need three numbers: the cost in the electric regime, the cost in the gas regime, and the switchover point between the two regimes.
    I just hate the miles-per-gallon metric because it is the inverse of the cost of consumption, which makes direct comparisons non-intuitive.
    I do prefer costs per mile because it makes the consumption metrics easier to apply at the point where you make decisions. Doing the depreciation & all is important for the big decision about buying/replacing the car, but once you’ve made that decision, you still have all the little daily choices of drive, walk, carpool, bike, combine…
    One recent example is that my cartop bag seems to cost me about 2c/mile, so taking it off immediately after I get to my in-law’s house might save me a dime, as compared to leaving it on to go to the restaurant and taking it off the next morning while the kids are asleep. Also, my commute is so short that I save only a quarter by riding my bike, but I do like thinking that these quarters add up. I’d pick up a dime if I saw it on the ground, and I’d forego a side trip at the drop of a dime.
    Plugin-hybrid-wise, it might make more sense to add a trip at lunchtime after a charge at work rather than add a detour in the 6c/mile regime.

  29. Anonymous

    I’m not saying your wrong or anything, but where are your numbers to back up your claims? Yeah, in all honesty electric plugin hybrids can’t really be compared to gasoline engines. Although I guess you could compute gasoline equivalents by determining the energy in gallon of gas, determining the efficiency of the converting gasoline into electric energy and then determining how many miles an electric car can get from that number.
    But please, if you’re going to call bullshit on something and start claiming other numbers… give us some calculations. After all, thats what this site is about right? Good math and bad math? There was no math here.

  30. Ricardo

    I want to express my disatisfaction with the author on this poorly researched article. As others have pointed out, GM did not make up the formula for computing MPG for vehicles such as this. The EPA did.
    If you want to blame someone for bad math then why dont you blame the EPA?
    The other problem is that the EPA is attempting to use a rational formula for determining MPG but the author does not even try to explain it or base their criticism on the methodology used to attain the MPG measurement. Instead the author chooses to bashe the auto maker. I guess the negative headline will get them more hits.
    I am very dissapointed to see such misinformation on a science site.

  31. Brian Schmidt

    IIRC, car companies are legally prohibited from advertising a different mpg from the one given to them by the EPA.
    I’d disagree with the post though – the average commuter mpg figure is correct for the average commuter. Similar criticisms can be made against the mpg figure used for standard cars – what if you lived in a really hilly city? A city with lots of traffic snarls where you sit and waste gas? A really cold city that reduces performance or a hot one that requires a lot of AC?
    Anyone who’s thinking of buying this car would quickly learn the specifics and apply them to his or her situation to estimate the mileage they’d get.

  32. Alex Besogonov

    “As I said in the original post, and I’ve said in the comments: you can’t realistically assess the efficiency of a plug-in hybrid with a single number.”
    Why not? EPA uses averages, so if everyone in the USA right now switched to Volt, then the average fuel economy will be 230MPG.
    Of course, for individual consumer it’s a bit meaningless.

  33. dhogaza

    Hank, the old EPA gave the same car 100 and 48 mpg ratings last year.
    This is the new government.

    Yes, the new EPA that understands that people will recharge a plug-in hybrid by plugging it in rather than running the gasoline engine until it has finished recharging the battery. Otherwise they’re not going to spend the extra money for a plug-in hybrid.
    The 100 mpg figure you cite was for estimated *combined* mileage based on tests of prototypes. The “new” government you disparage will lead to roughly the same result as the old, with the differences coming from the tweaking of the car, as the old tests were with prototypes and the final results will be from samples from the production line.
    The 48 mpg came from the EPA changing the test so that the battery had to be fully recharged by the gasoline engine at the end of the test, which is totally unrealistic. Apparently they’ve backed off that, as, again, the idea is to plug the thing in.
    The 230 mpg figure is for *city only* driving, nearly all on the battery.
    While all this might be “bad math” the reality is …
    1. GM is making it’s announcement based on EPA criteria. Good or bad, it’s not GM who set the standards. I don’t see anything wrong with them announcing the numbers that, after all, they are required by law to put on each car via a window sticker.
    2. It is for city driving only. Apparently for plug-in hybrids EPA has come up with a test format that results in the Volt’s (and, presumably, Toyota’s forthcoming plug-in version of the Prius, etc) running almost entirely on the battery.
    3. The information from GM, at least as reported by the NY Times, makes it very clear that once the gasoline engine is used, mileage drops drastically, and that the combined mileage figure will be in the 100 mpg range, highway driving considerably lower.

  34. scrappy

    “Good or bad, it’s not GM who set the standards.”
    A year ago (with the 100/48 mpg ratings) that would have been true. Today it is not: the majority (60%) owner of GM is now setting the standards. The majority owner of GM wants all Americans to move away from fossil fuel vehicles. Hence the mpg ratings change today, and the tax changes tomorrow….
    Pony up.

  35. E. Pluribus Unum

    The Volt does nothing to address greenhouse gases, however.
    It merely exchanges the combustion of gasoline in an onboard engine to the combustion of coal at a remote electrical power generation plant.

  36. to scrappy

    It takes 2 days to go from NYC to Boston on my brand new leaf (with 16 hour layover for charging)! meanwhile the ugly guzzling volt only takes 4 hours like any other car….

  37. dude

    You do realize that this is nothing to get outraged about? right? If you drive under 40 miles a day, guess what? you pay the same amount you would if you got 230 miles a gallon of gas. Something everyday people understand. It’s a headline, the best stuff always gets printed there, it isn’t unexpected. What is unexpected is someone to call this rubbish. Have you lived in a cave for the last 100 years of newspapers. Good god.

  38. scrappy

    dude, the problem is the math. This is straight from GM:
    “Applying EPA’s methodology,… a typical Volt driver would pay about $2.75 for electricity to travel 100 miles, or less than 3 cents per mile.”
    $2.75 is what I pay for 1 gallon of gas. I go 40 miles on 1 gallon of gas. The Volt will go 100 miles for the same cost (that’s at $0.11/kWhr, which is before Cap and Trade hits the coal plants).
    So how does the Volt warrant a mpg rating more than 5 times mine?

  39. MajorTom

    Thanks for breaking that down Mark. I’d saw this article on CNN and wondered what the true breakdown was.
    Wayne said, “One criteria that has to be considered with a electric vehicle is the cost and frequency of battery replacement. This will increase the cost per mile on this vehicle.”
    Wouldn’t that also apply to gasoline powered cars? If one includes the maintenance and service costs of the gasoline engine?

  40. James

    It’s only impressive until you realize that the majority of these owners will be fueling their cars from high emission coal burning plants instead of low emission gas engines.

  41. dean

    Update from tonight’s news: the EPA HAS NOT confirmed the mileage numbers GM claims for the volt. No word on when a decision will be made.

  42. George

    It’s good to see that Obama got politics out of science. I’m sure that the conveniently exaggerated mpg estimate from the EPA to boost the now government-owned GM is only a coincidence.
    I mean, it’s not like Obama would have any political reason to boost the Chevy Volt or anything. Nothing to see here, move along.

  43. Mu

    MajorTom, the replacement costs for the batteries likely exceed the cost for a standard car engine, and how often do you replace the engine compared to your batteries? Usually 1000 charge cycles is a good number for batteries, so if you charge 5 times a week 50 times a year that’s 4 years of life. If we assume the battery cost at only $4,000, that adds $1,000 per year, or $4 per charge cycle. Compare that to the 50 cents in electricity, and your battery cost are much more significant than the electricity itself. Even at double the durability and half the cost it would still be $1 per charge.

  44. Alexander

    In practice, you won’t get 50 mpg for the last 8 miles part of your journey because the motor has to heat up before it will reach top efficiency. In the first minutes after motor startup, it will more likely consume about 40 liters per 100 km, that’s about 6 mpg in medieval units.

  45. TW

    Be honest. GM is only saying what the Fed gave them for numbers, sure, not really the best way to figure it out for such a vehicle, but it is what the government gave them.
    These sorts of blogs bother the crap out of me. Be honest, don’t blame GM for numbers that they’re required to give like all other manufactures. That’s just stupid on your part and makes them out to be liars. If you wanna write about something worthwhile, write about how the government has stupid tests and the way they figure out MPG’s for all cars sold in the US isn’t very accurate.

  46. dean

    “t’s good to see that Obama got politics out of science. I’m sure that the conveniently exaggerated mpg estimate from the EPA to boost the now government-owned GM is only a coincidence.”
    George (and TW) keep up: the EPA (as of Tuesday evening) has not vetted these numbers: they are from GM only.

  47. Alex Besogonov

    “to scrappy, your new Volt won’t do that when it is released. Even the folks at GM say the little range-extender hybrid engine won’t be part of the vehicle when it is first released”
    Complete bullshit. Volt is now in the final stages of development (production of Integration Vehicles), it’s waaaaay too late to make significant changes.

  48. Nate

    For those of us paying attention, this is not bad math in the “Good Math Bad Math” sense.
    The claim is that for city driving

  49. Nate

    A less-than sign ate my last post. Here it is again, proper.
    For those of us paying attention, this is not bad math in the “Good Math Bad Math” sense.
    The claim is that for city driving less than 40 miles, the Volt consumes a particular amount of energy, call it E. For less than 40 miles the Volt runs entirely from battery, and so E was originally generated by a power plant somewhere. If you do some rough estimation, that power plant produces energy (from whatever source it uses) with the same efficiency as a theoretical 230 MPG car converts gasoline to energy.
    While converting from power plant efficiency to MPG is a bit flaky, it’s not “bad math” as Mark claims.
    This has nothing to do with efficiency on trips over 40 miles (Mark), comparison of costs to gasoline and doing a backwards MPG calculation by way of dollars (scrappy) or government conspiracy (everybody). It’s just a marketing statement trying to quantify the efficiency of the electric motor in MPG.

  50. Math Pragmatist

    So I’ll step up and claim that it’s not bad math at all. Realistically, most regular city drivers will drive less than 40 miles for the day. For the sake of argument, let’s say they drive 50 miles per day. Across a 5 day span, someone will drive 250 miles, 200 of which were “gas free.” The remaining 50 were driving off of an efficient gas motor, so the math could easily work out to an average of around 200 MPG. This would be a pragmatic calculation and requires you to relax the rigidity you’ve imposed in your analysis.

  51. Cobraphx

    Interesting that the author takes issue with the 230mpg figure. The goes on to state that both he and his wife will exceed this MPGe on a daily basis. Wish my car could do that.
    And the significant cost of recharging? The Volt uses 8kWh of it’s 16kWh pack, so as part of the author’s 288mpg, we need to figure out the electricity cost for his 48 mile commute. 8kWh + 15% loss for charging and battery controller inefficincies (this is probbly too high) is 9.2kWh a day. At 12cents per kWh (the national average) this is $1.10 per day in electricity to drive 40 miles. The extra 8 miles adds .13 gallons of gas ($3.00/gal) per day for a cost of $0.40. This gices us a cost of $1.50 to drive 48 miles per day. Compare that to an ICE car that gets 25mpg on the same drive and we see that the ICE car uses $5.76 to drive the same 48 miles. This gives us a cost equivelent of 96mpg.
    Where I live, I can charge at night for off-peak rate, that is currently $0.065/kWh. Using my electricity rate and $4.00/gal for gas, the Volt’s cost equivelent is even higher. $0.60 for electricity, $0.52 for gas with the gas car at $7.68… this gives us a cost equivelent of 172mpg.

  52. Karl

    The problem is the plug in part. Why not just create a whole system that charges itself–wait, Toyota Prius has done this already. It works, no hidden costs, mileage is actually the same as the already over-rated Volt all at half the sticker price. None of the plug-ins will be an efficient way to build a car. Some of us have to drive 50+ miles to buy groceries. What if you want to take a weekend and go somewhere with the fam; a kid’s ballgame to travel to? Or you have a business trip out of town? Will all the schools have to rewire their parking lots to accomodate this new technology? This 40 miles with no gas is peanuts. So what. I’d love to have the opportunity to buy an American car with convenient fuel efficiency. But I got tired waiting.

  53. Clarity Voice

    Sorry you’re completely wrong. This is not how they calculated MPG, and you really owe it to yourself to either delete this entry or put a clear retraction on it, because quite honestly it makes you look ignorant.

  54. efrique

    So a better way to describe it would be “the car that mostly runs on coal! (and natural gas, nuclear, hydro-electric, …)” because all that electricity comes from somewhere, and it would be ludicrous to count the small amount of gasoline a fairly typical driver like Mark might use and ignore the much larger amount of coal…
    Working out exactly how much coal you burn per mile is not simple – you can’t just convert the energy yield from burning coal and equate it to burning fuel – there are losses in the conversion to electricity, the transmission (over 7% right there) of electricity, and getting it into and out of the battery (every warm transformer is additional coal).
    If we’re going to be so crazy as to imagine running electric cars is “green” when we’re burning coal to generate the electricity, we probably should investigate whether it’s more efficient to just design cars to run directly on some form of fluidized coal (hopefully the scrubbers on the exhaust won’t be too prohibitive).

  55. Clarity Voice

    I see you’ve now lured in the “Coalers” who spout their hilarious attacks on electric vehicles. Seriously, delete this entry because you’re attracting the wrong audience.

  56. TonyP

    >>”If charging is usually done at night, it will be during off-peak demand hours. Maybe a good thing.”
    Although if/when cars like this become commonplace, the difference between day and night power usage may become less distinct, or even reverse. It’s hard to imagine the power companies retaining their current pricing models under those circumstances.

  57. Jason A.

    Karl @57:
    You should actually learn what a plug in hybrid is before you criticise them. It’s essentially a hybrid just like the Prius, BUT with the option of charging the battery from an outlet. You can still charge the battery from the engine just like the Prius. The Volt is not an EV (electric only). You can drive as far as you want whenever you want. All else being equal, plug in is a step above today’s hybrid like the Prius (which I own). What worries me about the Volt is GM’s poor quality reputation applied to a car that’s either going to be too expensive (projecting $40,000 range) or sold at a loss.
    Yeah, the coalers are ludicrous. Even deriving energy from coal plants (temporarily, as those are hopefully phased out) that’s still more efficient than a gas engine. Comments like #59: “there are losses in … the transmission (over 7% right there)” just show these people are latching onto any asinine reason to oppose new technology. Gas powered cars didn’t have transmission, I suppose [/rolleyes].
    The 230 mpg number is definitely misleading, in that people who see EPA ratings tend to expect their cars to get something similar. In most cars they do, but the plug-ins mileage has a huge range-dependent factor where the mileage could be anything from 50mpg (or whatever the gas-alone mode gets) to practically infinity. However, if they got the rating through the EPA specified test (which, as some have pointed out, the EPA has not verified this number yet) then it’s a marketing decision to play on people who don’t understand the testing.

  58. Jason A.

    Excuse me, I misread #59. They were talking about transmission of electricity through the grid, not drivetrain losses.
    Despite that, coalers still = ludicrous.

  59. bluemonkey

    This car has an Electric motor and a battery that must be recharged after 40 miles.
    If you will be the lucky one to kip this battery for 300 charge/discharge cycles you need a new battery set after driving 12000 miles (40miles x 300 recharge cycles). If the cost of the battery is $5000 , then you spend $0.4 per mile only in battery cost. Kilowatts, recharging the battery are extra.
    Oh, by the way, this car has a gasoline engine 40MPG.
    I bought a used Toyota Corolla, manual, on 2002 with 35000 miles. Now the car has 120000 miles and still makes 34MPG (Summer).

  60. Anonymous

    Marginal cents per mile is probably the most honest way of looking at a decent side-by-side comparison. With my driving habits (regularly drive 5 hours one way to some work appointments), a turbo diesel was the most economical choice. For others a “conventional” hybrid will be. For others still, a plug in hybrid will be.
    One factor that as far as I know is still unknown or at best “an estimate” is the average life of the batteries and expected total replacement cost including labor.

  61. John Denton

    The other end of the power cord needs to be discussed as well. When you plug a device in, then you extend your effect into intrusive technologies of varying degrees. The hybrid revolution is set to trigger a huge nuclear power investment at the current rate. Coal is the alternative to nuclear, but will work against whatever enviro meme that hybrid tech touts. Natural gas could produce electricity, and in impact would come in above coal in less lethality, but is there enough for long term investment? Looks like we’re going nukey, folks.

  62. Brian

    I think the public understands “miles per gallon” as a very simple metric: if my car that I use for average city driving has a tank with a ten gallon capacity and I get 25 mpg, I should get to go about 250 miles before I have to fill up (there are literally thousands of factors that would change that number). Within the context of that metric, the 250 mpg is fair. With the same 10 gallon capacity tank, driving the same way, I should be able to go 2500 miles before I have to fill the tank.

  63. Ray Burleigh

    An all electric car will never be practical in most climates (unless there is a tenfold increase in battery capacity). You would not be able to drive the Volt even 1 mile, on batteries alone, at night in January in Wisconsin. And it would be extremely uncomfortable driving it at noon in July in Arizona. Running lights and a heater/defroster are essential for any car. Most people will also want a radio. The effect of those on range and operating cost are never discussed. And, in some climates people will not accept cars without air conditioning.
    That’s why hybrids are such a great compromise. Heat for comfort and defrosting are “free” with gasoline engines, and they provide enough power to run the lights, radio, and air conditioner, when needed. Also, using the engine to run a generator, rather than the wheels, allows the engine to run at its most efficient speed regardless of the vehicle speed.
    A transmissionless electric drive vehicle with a combustion engine/generator for extended range and powering accessories is probably the best currently attainable solution. But in most of the country, for large parts of the year, it will not be driven on batteries alone even for short trips.

  64. Hawaii mike

    GM has been talking about the chevy volt since 1999 or earlier and is the same year they hired repo men to go out and confiscate all of the 100% electric vehicles that were getting 150 miles-per-charge EV1s leased out in CA. All of these perfectly good cars were scrapped. Look it up.
    Really, If GM wanted to produce a car that was 100% electric or 300 mpg it would already be producing them. Its hard to for most people to face facts, but just like a cheating spouse, the facts about loyalties speak for themselves. Really. Really. Wake up people.

  65. Kris Rhodes

    According to GM, an average charge after a daily commute using the same scenario that produced the 230 mpg would consume about 8 kilowatt hours. The most recent figure I could find for the average cost of a kilowatt-hour for residential electricity users is for June of this year, when it was around 5.7 cents per kwh. So the daily charge-cost for driving somewhat under 40 miles per day on average works out to around 50 cents per day of electricity. Compare that to gasoline, where an average car will consume at least one full gallon of gas for a comparable distance, and the plug-in hybrid really does look great.

    Or you could RTFPL.
    In the press release, GM actually uses fairly measured words, and gives their own estimates for cost/use.
    I think their bullet points at the beginning are eminently fair, even if the media (here included) overblow and hype things to agree with themselves.
    Your complaints about how this is being represented isn’t the fault of GM. It’s the fault of the media, and people like you, not thinking before you speak. Do yourself a favor and act like a scientist— look at a primary reference before mouthing off.

  66. Kuroki Kaze

    Haha, i saw this car in news today at morning and thought exactly the same thing 🙂 — they “forgot” to mention how much electricity it takes to go these 230 miles.

  67. Chris

    Even at 230 mpg, and an average cost of 2.50 per gallon, this car will cost more to run for 6 years than a typical car getting 20 mpg. Numbers used to calculate: Volt cost = 40,000, typical car 20,000. Average miles per year = 12,000. Cost per gallon 2.50. Years of ownership = 6. Not factored – out of warranty repair/replacement parts costs over 6 years. I’m thinking it will still cost 7-8000 more to own a volt than a corolla.

  68. Myron

    I want to like the Volt – but – the price tag of 40,000 makes it prohibitively expensive for me.
    My commute is roughly 16 miles each way (32 miles per day) on some days I include a stop for a bagel or to take my son to daycare (35 miles per day). I drive a “don’t laugh it’s paid for” Toyota Matrix. So I have a feeling it will be a while before I get something else. On a recent road trip (almost all highway miles) I got 37.3 mpg, and for daily driving I’m usually getting 33.1 mpg.
    We just got a 2010 Prius for my wife, I’m anxious to see how that works out.
    I do appreciate your time in braking down GM’s erroneous math – 230 MPG does seem like a tall tail 🙂

  69. Bill T

    Problems w/MarkCC carping about GM mileage. It’s better than what we’ve got. Progress is made. It’s gets better with every version, except for “Chrome”. Get out of the cubicle, away from the lala land of the CRT and join reality.
    The market will decide if it works. It’s a risk for GM to make this car. Let them reap either the rewards or failures for taking this risk.

  70. Guzmanistan

    I agree, its underhanded to label the car’s MPG the way they did. That figure has also NOT BEEN approved by the EPA yet.
    What we should do for hybrids (and electric cars, perhaps) is calculate it in units of energy, and convert it to volume of gasoline that “would” be consumed…gallons of gasoline equivalent. Additionally, total miles of travel possible and a curve of consumption by distance could be useful.

  71. Bill T

    Hey naysayers, get off your backsides and do it better if you think that you can. Hush up or put up. If you don’t want one, don’t buy one.

  72. Chris

    @#78 – good comments there Bill. Dont worry yourself to try to protect your fellow man from making a bad decision that will profit others. Kinda like Bernie Madoff – if you dont want to invest, dont. If you want to get duped, it’s your fault for being gullible. Or a payday loan place. Who cares if you end up in a endless cycle of debt, as long as you got some cash to buy your 40…

  73. Anonymous

    This story is a misrepresentation of reality. It’s an EPA estimate, and that estimate includes the cost of electricity. All hybrid/electric’s do the same thing so the average consumer can easily compare COSTS, not an actual number. #70’s post is fairly accurate.

  74. usagi

    It’s just dumb.

    Mark, it’s GM. The company that took a great car (Saturn) with a rabidly loyal user base (think somewhere between Mac heads and Twilight fans) and managed to turn every product in the line into utter crap, alienate the true believers, and generally run the brand into the ground and grind their reputation to dust in the space of a few years. Some of us still driving our mid-90s SLs are hoping for a turn around now that the company’s been purchased by someone who at least knows what qualities a good car possesses, but really, “GM” and “dumb” in the same sentence is redundant.

  75. Tyler

    “The “real” effective mileage (excluding the cost of charging the car – which will be significant!) varies depending on the length of your commute.”
    GM isn’t keeping this a secret. They explain it themselves.

  76. Dave

    I’d just like to point out the the Tesla Roadster, an all electric high performance all electric sports car is rated by the EPA at 135 MPG without burning a single drop of gasoline or diesel. The EPA methodology didn’t forget anything, it simply uses admittedly fuzzy numbers to equate energy from gasoline with energy from the socket.
    Because energy from the socket is less than 10 cents on the dollar compared to what you get from the pump it’s not unreasonable to say that for the duration of the EPA test ~50 miles, the Volt has 1/10th the operating costs of a 23 mpg car.
    The batteries also have a 10 year/150,000 mile warranty, batteries today are much different than batteries even 10 years ago and onboard software carefully controlls the charge/discharge cycles to maximize lifespan. To my knowledge Toyota has never had to replace a Prius battery under warranty.

  77. Chris

    At this point, all that matters is that people know the name Volt, are linking it to insanely high gas mileage. The fact that they are outed–and I imagine a New York and L.A. Times article coming soon–won’t really hurt them. More people will know the name and when they find out they can get 100 mph, they will still be impressed as you mention. You know what they say about publicity. The release is far enough down the line that people will almost forget about the initial outrageous 230 mpg claim and will be happy with the 100. But an outrageous number like that gets a lot of attention and sticks in people’s minds, especially after they see commercials about it, CNN talking heads going on about it, and countless articles.
    Knowing that this is how some business works…it kind of makes you sick. 🙂

  78. Aaron

    To #78 and #79:
    Can we do better than 230 miles per gallon of gasoline? No. If we were 100 precent efficient, we could barely propel a baby that far without and engine or anything. Think of a baby rocket, you pack it with gas and let it fart itself with perfect combustion around on wheels without friction.
    As per getting duped: when has it become okay for the government to lie to us? If I said I had a cure for cancer and it killed everyone who took it, it was their fault for taking my medicine? Get Real

  79. Lucas

    From now on we should measure miles (or kilometers) per $ dollar (or insert local currency) instead of miles per gallon.
    Far more honest that way.

  80. fred Sanford

    @ – milage figure:
    GM released a number based on *proposed* EPA tests.
    The number is BS – for some of the reasons listed above, but also because to correctly gauge an EREV (see below) fuel milage you *have* to ‘fill it’ – both gas and battery – then empty it. Alternatively, empty the battery, and fill the tank.
    Determine your travel distance (Dt), subtract battery only travel distance (Db), then divide the remaining distance traveled by amount of fuel used (gal). So…
    MPG = (Dt – Db)/gal.
    This number will vary (just as it does for ICE cars) due to travel type (highway/city), terrain, weather, and power accessories being used (A/C, headlights, wipers, stereo etc).
    @ Batteries –
    The batteries currently being used are Lithium(-ion) based. Ever have your laptop (or phone) go dead too soon?? There are no major environmental problems with Lithium batteries – at least not in the same fashion as lead-acid (I am talking disposal, not manufacture). There are other issues – rupture of the lithium cells for one. Ever read about Laptops catching fire?
    In the near future there will likely be a slightly different battery available Li-Fe these batteries show promise for longevity (more cycles), and far less problems with rupture/fire. They (as I recall) also have a higher energy density – more power in the same space/weight.
    @ Plugin Hybrids vs Hybrids (Prius, Insight et al) – some terms
    ‘Hybrids’ – are vehicles which have *2* drive systems. 1 powered by gasoline, 1 powered by electricity. These are MUCH MORE complicated – mechanically – then either a pure electric or pure gasoline (ICE – internal combustion engine) as either of the latter have only one drive system. Hybrids, effectively, turn on/off one drive system. For example a hybrid may travel mostly on gas until there is a need for more power (climbing a hill or passing a truck) when the electric motor adds additional power (or vise versa).
    ‘Plugin Hybrids’ – there are 2 definitions here 1 is better called an Extended Range Electric Vehicle (see below). Technically – a plugin hybrid is a hybrid (see above) which can be attached to an electricity source (wall socket) to charge its battery (rather than using some gasoline from the on board ICE to do this (this is what the Prius et al currently do).
    ‘EREV’ – Extended Range Electric Vehicle – This is an Electric vehicle (see below) which also carries a fuel tank and small ICE which is used *exclusively* to generate electricity which charges the batteries, and does NOT participate directly in movement of the vehicle (as a ‘hybrid’ does). The Volt and Aptera 2h (see are 2 examples.
    Electric Vehicle – this is a vehicle which is driven entirely by electricity. Electricity is usually stored in batteries, although most prototype fuel cell vehicles are EVs with the electricity being stored as ‘chemical’ energy in the fuel cell.
    Thank you reading this far 🙂
    You may now continue ranting 🙂

  81. Dave

    To 86
    Equating outright lying to the 230 mpg claim is dishonest in itself. We get it, the comparison between gas and electric vehicles is hard, if you have a better metric that consumers will understand go nuts. We know electric vehicles are much more efficient than traditional vehicles because electricity at the plant has the benefit of economies of scale.
    Unfortunately our battery technology isn’t good enough for an all electric solution so you end up with hybrids. When batteries can be charged in

  82. Rebecca

    One important fact you all are missing. GM hasn’t set the price for the Volt yet. The cost of production for the Volt is comparable to that of a $40,000 car. They have not said that they would introduce the Volt at $40,000. Also, there is a $7500 tax credit that comes with the Volt. In addition, GM is also considering subsidizing the cost of the Volt to make it more affordable to consumers in its first year of production.
    “Henderson conceded the cost of building a Volt will be expensive, about $40,000 per vehicle. But he said the vehicle will qualify for a $7,500 tax credit, which will reduce the vehicle cost by that amount for consumers.
    He also stressed that GM has not set the pricing for the Volt, and conceded the company may have to subsidize the vehicle. The goal: Make enough sales to move the Volt from “first generation” to lower-cost future designs.”
    I really wish people would read the entire write-up before criticizing things that they don’t know enough about. Read the ENTIRE write-up before throwing insults that make you look ignorant.
    Also… if you are commuting more than 40 miles per day… than this vehicle may not be a viable option for you but even at $.50 a day in electricty… that is still a lot cheaper than gas as gas prices continue to rise. If the vehicle isn’t right for you… great. That doesn’t mean it isn’t a great vehicle for the type of person it was designed for.

  83. Rob

    I don’t think it’s misleading at all: “If I fully charge the car battery every night, how far will I drive the car in typical city commuting conditions before it’s consumed a gallon of gas” = miles per gallon in this automobile.
    I’m not promoting the Volt, I could not care less about the car, but I beleive this is a fair declaration. Who says that mpg is equatible to continuous use of the gasoline engine?

  84. brodie7838

    I love the idea of the Volt, and am glad to see that technology like this is making such progress, but I think after what GM has pulled with bailouts, and that it is now owned by the US and Canadian government that I will not be buying any of their products.

  85. WhyDingo

    I wish that you wouldn’t call it a “Metric Error”. I’m smart enough to know that it hasn’t nothing to do with the metric system of measurement, but I fear most people are not.
    If your post continues to take off, CNN, AP and the likes will use it as fuel to scare Americans away from the system that you refute along with other winning states like Burma.

  86. Andrew

    I feel like the majority doesn’t understand how the efficiency depreciates based on how many miles are driven per trip. The actual mileage if you were to take a trip would probably be much closer to 53 MPG The mileage, based on info from Chevy, can be graphed as y=x/((x-40)0.02))
    Anything over about 75 miles seems to be in the middle to upper 50s. That is easily achievable with turbo-diesels from VW or BMW, and they start below the 40K mark. Vehicles that get 50 plus are great, but why reinvent what is already available.
    The other question I have is are these batteries going to opperate like my laptop? In 3 years will it only have a range of 20 miles?

  87. Saam

    I am no expert, but normally these types of cars have the ability to regenerate the battery when breaks are pressed. So, if the total charge is for 40 miles and the car is being driven on a stop and go traffic then one could possibly drive for much longer than just 40 miles on a single charge.

  88. Terrance New

    What a dumb article. It was obvious from what GM said that the mileage could vary. Why are knocking them? They didn’t lie, they told you the scenario. What a dumb blog.

  89. Bambleweeny57

    While I concur that statistics can hide any evil, I have to point out that there’s seemingly a glaring contradiction in your own estimates above.
    The following two statements from above seem to be describing an identical scenario. However, you claim that one supports 230mpg while the other supports 100mpg.
    They compute it by basically saying: “If I fully charge the car battery every night, how far will I drive the car in typical city commuting conditions before it’s consumed a gallon of gas”.
    What if you drive your volt around the city all day? Your mileage will drop to around 50 miles per gallon once you’ve driven more than 40 miles. If you drive your car 100 miles in a day, you’ll consume a bit over a gallon of gas.
    Maybe I’m missing something, or maybe someone should be a little more careful before criticizing GM & the EPA’s arithmetic.

  90. Anonymous

    No one is mentioning “charging time”. According to GM the battery has a capacity of 16 KWH. To fully charge it you would need about 20 KWH, (combined efficiency of 80%, Battery and charging/control circuit). Charging on 110V will take 12 hours and on 220V 6 hours. There is no way around it!

  91. Brian Schmidt

    “Charging on 110V will take 12 hours and on 220V 6 hours. There is no way around it!”
    Yes there is.
    Most drivers won’t take the battery down to fully discharged before plugging in.
    And as workplaces get used to electric cars, charging during the day will also become available.

  92. Anonymous

    “As workplaces get used to electric cars, charging during the day will also become available”.
    No problem, I am sure Home Depot has a 1000 ft extension cords.

  93. Chas

    This will feed the conspiracy theorists who believe that oil companies and car makers have been hiding technology like this for years to keep profits high.

  94. Kinglink

    GM has taken what is the single best thing they’ve done this decade and made it into another crap sandwich with these lies. Anyone should applaud this car’s production but now it’s become BS. Can I even expect this to live up to the hype, or is it more likely I’m going to expect it turn out like the Prius (a status symbol that hasn’t changed a thing) now that I’ve been directly lied to as a consumer.
    The bigger problem is that it’s far from cost effective even. People are running the numbers If instead of getting a Volt (assuming you never pay for gas) you buy a Prius, you could get between 8-12 years worth of use and gas for the same price as the 40K they’re expecting for a Volt). Now I understand new technology = price. But at the same time the Volt will live as a status symbol, rather than the messiah GM wants us to think it is, until it drops to a reasonable price as well.
    The real issue is I already have to remember to plug in my Ipod and phone at night, I forget sometimes. But now I have to remember to plug in my car as well? It’s going to be a good amount of hassle, though it seems like it could be worth that. (Granted where are you going to plug it in on the road or at work or such)

  95. bluemonkey

    This car has an Electric motor and a battery that must be recharged after 40 miles.
    For NiMH Battery pack:
    If you will be the lucky one, to kip this battery for 300 charge/discharge cycles, you need a new battery set after driving 12000 miles (40miles x 300 recharge cycles). If the cost of the battery is $5000, then you spend $0.4 per mile only in battery cost.
    For Lithium-ion Battery Pack:
    If you will be the lucky one to kip this battery for 900 charge/discharge cycles you need a new battery set after driving 36000 miles (40miles x 900 recharge cycles). If the cost of the battery is $15000, then you spend $0.4 per mile only in battery cost.
    And after, 1 year on use, the battery must be recharged after 28000 miles. That means $0.53 per mile only in battery cost.
    Kilowatts, recharging the battery are extra.
    Oh, by the way, this car has a gasoline engine 40MPG, or $0.065 per mile.
    I bought a used Toyota Corolla, manual, on 2002 with 35000 miles. Now the car has 120000 miles and still makes 34MPG (Summer), or $0.076 per mile.

  96. Dennis Forbes

    “If you will be the lucky one, to kip this battery for 300 charge/discharge cycles, you need a new battery set after driving 12000 miles”
    Complete and utter nonsense, remarkably repeated multiple times. Delete this stupidity.

  97. Chris

    I have to say, that while it may be a little misleading I feel that its ok with me. If you can tell me that I’m going to only need a gallon of gas for my daily city driving activities to get 285 miles per gallon I think thats great.
    If you do the math on the charging time vs a gallon of gas. 40miles/0.5 dollars to charge = 80 miles per dollar. Average gas price of $2.50= that is about 200 mpg. Thats not too bad. Depending on your prices you have some wiggle room for the final outcome.
    As far as the battery is concerned, if it last ten years with some degradation, say to 30 miles per charge. Thats not too bad either. A lot of research is going into these types of batteries than has been in the past. Give yourself 10 years, replace the battery in the car with an up to date model. Then you’ve got a new car.
    Most people today have delusions of grandure, like the above “get lost tree hugger” commentors. They believe that they need to have the most powerful gas hungry thing around. They also think that tree hugging is a bad thing. They also think that we have no responsibility to contribute back to the world from which we take.

  98. David

    Mark C.,
    You indicated an average price per kWh of 5.7cents. The average price per the US Energy Information Administration is 11.6 cents/kWh. GM reported that the electrical charge required per 100 miles driven on electric is 25 kWh. The 25 kWh equates to $2.90 for a 100 miles. If gas is $2.90/gallon the equivalent miles per gallon is 100.
    The Electrical power (25 kWh) that is required to charge and drive the Volt on electrical power for 100 miles is 85,325 Btu’s. A gallon of gas equates to 116,000 Btus. The mileage equivalent based on this conversion is 135 miles/gallon. The power plant efficiency is typically only 40%. This results in 2.5 gallons burned at the power plant to provide 1 gallon energy at the receptacle in the home. Thus, the equivalent efficiency for the electric Volt is 54.4 miles/gallon. Slightly less than the reported 230 mpg based a EPA method that has not been finalized or adpoted for OEM use.

  99. Lynn Crawford

    I am very interested in the Volt claiming a 230 MPG rating. I would like GM to publish its calculation. It is difficult to predetermine the HP required to move a Volt 40 miles. If the gassoline engine would yield 50 MPG (I.C. Car Engines have a thermodynamic efficiency of about 27%). If a gallon of gassoline has 120,000 BTU / Gal. The BTUs required to move 40 miles @ 50 MPG would be-
    120,000 BTU * 40 miles / 50 MPG * 27% = 25,920 BTU.
    Assuming the electrical system would achieve 100% efficiency and 1 KW-hr of electricity contains 3,416 BTUs.
    40 miles using 25,920 BTUs mechanical energy from a 100% efficiency electrical source would consume 25,920 BTUs / 3,416 BTU / KW-hr = 7.5 KW-hr.
    If one gallon of gassoline costs $2.50 * 40 miles / 50 MPG = $2.00.
    GM assumes that I will get 7.5 KW of electricity at my home for $2.00 * 50 MPG / 230 MPG / 7.5 KW-hr = 5.8 cents / KW-hr.
    I believe that my home electric bill would be over 10 cents per KW-Hr. If this is correct I think that the 40 miles of driving without the use of the engine would achive a 133 MPG equivalent (based on my electrical costs).
    I wonder if this is what GM’s calculation is? I think that a break from petroleum is a step in the right direction, but I can’t get the math to compute to 230 without (atleast) 5.8 cent per KW-hr electricity. If the Volt can perform at these efficiencies it may move us away from petroleum and on to Natural Gas / Coal / Hydro / Wind / Solar electric sources. A Natural Gass powered electrical plant has a thermodynamic efficiency of over 40% which could reduce carbon loading by more than 35% from current car emissions. Coal electric would load carbon at about the same rate but at a lower cost to the Volt owner.

  100. Anonymous

    “The honest way to describe it is to say “Up to 40 miles without consuming gas, and then 50 miles per gallon”. That’s not so horribly difficult, now is it?”
    The writer does not know a thing about basic marketing. Which marketing fool will advertise with the plain facts ?
    Marketing can honestly advertise as the “90 miles per gallon” car. They correctly describe that the glass is half full, while the critics cry out the glass is half empty.

  101. Anonymous

    Looks like we’ll need to use a new unit for measuring the efficiency of a hybrid…
    MPkW – miles per kilowatt

  102. nanoAl

    I think they are doing the same thing that tesla motors does when they say that the model S gets about 300 mpg. it doesn’t run on gas so an mpg rating is stupid. Its battery holds the same amount of energy as 2 gallons of gas and it can go 600 miles.
    Nitpick: the Volt is not a plug-in hybrid. it’s a series hybrid. the gas engine only provides electricity for the motor, which runs the car. You can buy plug-ins that’ll directly plug your hybrid into the grid, so Gm is just giving one of these stock in the most inefficient variety of hybrid (parallel ala civic or series-parallel ala camry is much more effective).
    Its odd that there is so much hype. I remember reading somewhere that the prius can go 60 miles without using any gas, and when the engine is running, it gets a lot better than 50 mpg, hell, a corolla gets 53. why the hype for a car that is significantly inferior? even the Saturn EV1 in the ’90s was better, what gives?
    can we all just take a moment to laugh at GM?

  103. Rebecca

    The Volt IS a plug-in hybrid. You have to plug it in to recharge the battery. The gas engine allows you to extend the driving range of the vehicle because not everybody restricts their driving to 40 miles or less per day.
    Come on people really? If you don’t like it don’t buy it. Stop hating.

  104. Anonymous Coward

    I agree with you on the calculations etc. I think it’s stupid that you’re getting angry that they expect you to charge the car every night. You keep mentioning “thats assuming you charge it EVERY NIGHT”. That’s really not such a big expectation. That’s like getting upset that cell phone manufacturers expect you to charge your cell phone every night to get 5 hours of talk time and responding – Yeah 5 hours…Ugh! Assuming I charge it EVERY NIGHT!!!. Of course they expect you to, as you should if you want the kind of results they’re promising

  105. Jeff

    One barrel of oil produces 1700 kWh of electricity. One barrel of oil also produces 19.5 gallons of gas. If the Volt can go 40 miles on an 8kWh charge, that comes out to 435 mpg. In general, your mpg conversion has to be based on what you think is the important commonality. For me its barrels of oil consumed. For others it might be dollars, pollution, etc.

  106. Eric

    The Tesla folks have (or at least, had) a good whitepaper on the full life-cycle costs of electric cars that is worth a read…

  107. vivian

    Here’s my math on the topic with the following assumptions:
    1. Increase in initial auto cost or similar vehicle $20,000
    2. Increase in auto’s resale value $10,000
    3. Increase maintenance cost (replace batteries, etc.) unknown.
    4. Increase in annual auto insurance $300
    5. Lost interest on additional initial cost annually at 3% simple interest $20,000 x 0.03 = $600 per year.
    6. Driving 40 miles per day, gas cost regular vehicle $3/gal at 20 mpg = $6 per day versus $0.50 to recharge batteries = saving of $5.50 per day x 365 days = $2,007.50 per year fuel saving.
    7. $2,007.50 – $300 insurance increase – $600 lost interest = $1,107.50 per year net savings.
    8. $10,000 net increase in cost ($20,000 – $10,000 resale value) / $1,107.50 per year net savings = 9 years to break even before you start saving money.
    Doesn’t take into consideration tax incentives, taking vacation trips that rack up miles without energy savings, etc. Change the numbers for your own assumptions using the same formula as you would like.
    I’m all for reducing fuel costs but I think it should be at reasonable costs to consumers. Also why about engineering some sort of built in wind generators that recharge the batteries as you drive? To get this vehicle to justify the added cost, you need to be able to drive it around the country at a low mpg.

  108. David

    The combustion of one barrel of oil produces 5,802,000 Btu’s. The conversion efficiency of a power plant (40%) results in a kWh output of only 680 not the 100% efficiency you assumed. The charges at 8 kWh per charge are 85 yielding 3,400 miles per barrel of oil. Using your 19.5 gallons of gasoline 174 mpg would result.
    However, the 42 gallon barrel of crude oil yields 19.5 gallons of gasoline but also produces 9 gallons of fuel oil, 4 gallons of jet fuel, and 11 gallons of other products, including lubricants, kerosene, asphalt, and petrochemical feedstocks to make plastics. These are all useful products and cannot be ignored simply becouse the conversion only yielded 19.5 gallon of gasoline.
    A more realistic approach is to use at a minimum 32.5 gallons of fuel output resulting in 104.6 mpg which fails to take credit for the value lubricants, kerosene, asphalt and petro feedstocks.
    An update from the GM press release states that 25 kWh are required to provide the charge for 100 miles. Using this charge requirement per 100 miles and 19.5 gallons of gasoline from 42 gallons of crude, a mileage of 139 mpg results. A more realistic assumption that 42 gallons of useful products result the vehicle milesage is 64.7 mpg. This is credible mileage for an electric vehcile versus the 230 mpg reported.

  109. Bill

    Get over yourself man… their using an average commute distance of 46 miles per day which is close enough. And duhh of course your going to have to pay for electricity to charge the batteries I don’t recall anyone saying they were magic batteries that last forever. Oh and btw you’ll eventually have to change the tires too. It’s a shame that we can no longer get excited about something in this country without some JA complaining that they weren’t told they had to roll their windows up at the carwash.

  110. bluemonkey

    @ Dennis Forbes;
    We are hire to discuss, not to humiliate each other,
    The battery pack itself, rated at 16 kilowatts/hour, comprises more than 220 separate cells wired in series. That means the failure of any one cell disables the entire array, though some existing hybrid vehicles also have this flaw. The Volt pack is about six feet long and weighs a hefty 375 pounds.
    Voltage: 320 – 350 V
    100% recharge time:
    110V outlet: 6 – 6.5 h
    Electromotor: 45kW
    GM also claims the 2011 Chevrolet Volt can run solely on electric power for 40 miles with a full battery charge. That’s in line with studies showing that most Americans drive only about 40 miles a day, so in theory at least, a Volt could go for weeks without using a drop of gas or spewing any CO2. But some analysts think the real-world electric range will be closer to 30 miles and probably less, depending on vehicle speed, ambient temperature (which affects battery performance), and whether trips include steep grades.
    After how many recharge cycles (DAYS) the Battery Pack 16KW/H with 220 separate cells wired in series, weighting 375 pounds, HAS TO BE REPLACED WITH A BRAND NEW ONE?
    If this car will be used as a normal hybrid car:
    If the battery pack is fully charged overnight, the fuel tank filled with gasoline (gasoline pump shuts off) and the car is driven non stop 230 miles:
    Going beyond Hybrid, GM and his rescuers are going down a cliff.

  111. Rhett

    I thought I submitted this comment, but I must have done something wrong. If it appears twice, please forgive me.
    So, I think there are really 4 (or more) things you could calculate:
    – actual MPG (how far you go divided by how much gas you use). This, of course, will depend on how far you drive before recharging.
    – equivalent mpg. this is like how much energy (in terms of equivalent gasoline) the car uses per mile.
    – mp$ – this is how far you can go per dollar. This also depends on how far you go between charges
    – miles per kg of CO2 – also depends on how far between charges.
    Here are my calculations:

  112. Cobraphx

    It is amazing the amount of ignorance so openly expressed in response to a single blog article.
    Electricity costs about 9 cents per kWh average in the US (you can find this price for your area on your electric bill), the Volt gets about 4 miles per kWh, so about 2.25 cents per mile to drive in electric mode. Volt seems to get around 50 miles per gallon on gas, gas is $3.00 per gallon now, or 6 cents per gallon. If gas goes to $4.00, 8 cents per miles, $5.00 10cents per mile. If you are driving a 33mpg vehicle gas is costing you 9 cents per mile.
    Sure, the electricity comes from somewhere, in the US something like 48% of power is from coal. But the coal plant CAN be cleaned up and the CO2 captured, and the polution is moved out of the city. You can’t do that with the thousands of cars that are driving around pouring pollution where you live.
    The Volt does have A/C and heating, it also has a radio, electric windows, and a digital information center just like any other car. It provides the fuel economy of a good hybrid, while giving you the option of driving 30-40 miles per day using electricity without consuming a drop of gas for those miles.
    A gallon of gasoline contains 35kWh of energy. A kWh of electricity contain a kWh of energy. The Volt according to GM gets about 4 miles per kWh (25kWh/100miles). 4 times 35kWh is 140 miles. Not sure how the 230MPGe is calculated.
    The Volt will be sold with a 10 year 150,000 mile warranty on the battery pack. It will likely last far longer than you want to drive a GM car.
    It is a GM vehicle, so I have to be skeptical of the quality . But maybe they will surprise me.

  113. DaveB

    After reviewing numerous documents regarding the upcoming 2011 Chevy Volt being designed by GM I perceive the following problems:
    BACKGROUND: the car Is being designed to be used only for short trips of about 40 miles powered by a 400 pound Lithium Ion battery and a 149hp electric motor. It has been estimated that this will serve the daily needs of most users going to and from work. The car is then to be plugged into a standard AC electric
    outlet and recharged during the night and be ready in the morning for another daily 40 mile trip. Learning from their previous electric car disaster the EV1, GM is also including a 100hp gasoline engine with 7gal gas tank that will drive a large generator that will power the electric motor if/when the battery can no longer do so. This is take place primarily if the driver continues to operate the vehicle after driving it for 40mi and not recharging it. The gas powered generator is not allowed to recharge the battery under any circumstances.
    PROBLEM 1: is purchase price. I do not know many people who are ready, willing and able to pay $40,000 for a small car to drive back and forth to work on a daily basis. Sure there are a few that will buy it but not nearly enough to make this product profitable. And all of the current “hype” that it gets 230mpg is all smoke and mirrors as new measurement standards are being developed by the EPA.
    PROBLEM 2: is operating costs. Most areas of the country have tiered electrical rates. In other words recharging their Volt on a daily basis adds to highest rate that they are paying for all other utilities which is greater than the baseline rate quoted estimated a $.03 per mile cost. Realistically it is more like $.05 per mile which “equates” to about 60mpg without the AC on… Additionally, today’s gasoline prices are going down and electric rates going up putting a damper on the long term outlook. When driven more than 40 miles the volt is no better than most hybrids on the market today that cost a whole lot less and deliver about 50mpg.
    PROBLEM 3: when everything is running according to plan the gasoline engine, tank and generator are “excess baggage and costs” used only for an emergency. I think that it would be a lot smarter to eliminate them and have warning lights indicating when the battery is getting low and will need recharging. The EV1 was too limited in mileage for this to be effective.
    PROBLEM 4: if the driver wishes to use this car for much longer trips or on vacation the battery becomes 400lbs of excess weight and there is no easy way to temporarily remove it for this usage. I think that GM should include a switch that will allow the driver to recharge the battery while driving more than the 40 mile limit making it more like all of the hybrid vehicles that are now available.
    PROBLEM 5. most people are not going to like having to plug in their car every night to recharge it especially in the winter or when it is raining. Additionally many drivers do not have easy access to an AC outlet, especially those who live in apartments and some condominiums.
    PROBLEM 6: we have all been using Lithium Ion batteries for the last 10 years in our cell phones and laptop computers and have not experienced one to last more than 3 years with good functionality. And we do not subject these devices to outdoor summers of Arizona or winters of North Dakota. The battery in the Volt costs about $8,000 and will have to be replaced about every 3 years regardless of what the warrantee states. GM will not be able to continue to support or sell additional Volts until this problem is solved which will require a totally new design which is being partially funded by our government at this time.
    PROBLEM 7: is depreciation. With technology changing so rapidly the value of a 2011 Volt will decrease rapidly. What else is new?

  114. Zaps Infinitum Expensos

    “The electric also leaves the hope for a better electrical generation system. We don’t have a large scale viable system in place yet, but it’s possible that we’ll develop one.” 5.7cents per kw/h today, the e car sounds great- when the grid gets an overhaul with cost over runs of Billions of dollars, new access fees and strange adapters will be developed to screw consumers into being the next generation tax drones. 5 bucks a gallon for gas will seem cheap in 15 years..

  115. Chris Preuss

    I’m the GM VP of Communications…and the dialogue here is great. As for bad math, the author left out that this is “city” driving. We stated clearly the composite EPA mileage will be triple digits, with a 300-plus mile range. It’s EPA’s test, we simply ran the numbers. If people think we’re being deceptive, than the entire industry is with what’s on the EPA label. And if all this is bad thing, I guess we’re out of ways to change perceptions. As for the idea we won’t have it out in 2010, we’re still on track for our November 2010 full volume startup. We showed the pre-volume prototype builds to the press at the program on Tuesday. The whole point of the 230 campaign was not to mislead or over-hype. It was meant to remind people that we’re in business, we’re a vastly different company and we want to change the discussion. The debate here is exactly what we wanted to spur…scorn and all. We’re listening and thank people for weighing in.

  116. Doug

    12 mile commute, 24 mile commute – 45 miles?! That’s your problem right there. I was annoyed when my commute became 2 miles and I had to cycle instead of walking…

  117. Mark C. Chu-Carroll

    Re #132:
    Life isn’t always as simple as we might like it to be.
    My wife works for IBM. Her office is located in the middle of a hellhole corporate park in Westchester county. There really isn’t any decent residential area less that five or six miles away. It’s actually 9 miles door to door from our house – but she needs to drop off our kids, which adds a bit of distance.
    I work for Google, which has an office in the Chelsea neighborhood of Manhattan. Even if my wife didn’t work up in Westchester, there’s no way we could afford an apartment big enough for four people within walking distance of my office.
    Most of the people I know have similar problems. The odds of two skilled people finding jobs within a very short distance of an affordable residential area just isn’t very likely.

  118. David

    There is a saying somewhere relating to glass houses and rocks. Perhaps you are famliar with the saying but choose to not subscribe.
    Your conversion of a gallon of gas to 35 kWh assumes that the combustion of the fuel (gasoline) is 100% efficient and that the conversion from heat energy to electrical is 100% efficient and the tranmission of electrical energy from the power plant to the residence is 100% efficient. Reality is that only 40% of the power plant fuel input energy reaches the residence. Correcting your 140 mpg equivalent mileage for the losses at the power plant and thru the distribution system, the Volt operating on electric energy results in an equivalent mileage of 56 mpg for electric mode operation.
    The 230 mpg GM advertises excludes the electrical energy required to charge to batteries because gas is not being burned for charging. An assumption that is as valid as assuming that GM will remain in existence for another 10 years.

  119. SLC

    There’s another problem here which is that the 40 mile distance on a full battery charge is dependent on how the car is driven. If the vehicle is driven on the freeway at, say, 55 mph, one won’t get anywhere near 40 miles on a full battery charge. Unlike a conventional internal combustion engine, the distance an electric vehicle can travel on a full charge drops off with increases in average speed. A conventional internal combustion engine actually goes farther on a gallon of gas as the speed goes up until somewhere in the mid 50 mph range after which air resistance takes over and the distance per gallon drops.

  120. Tony

    If the reason for the inflated MPG number is understood, why does it even matter? If you didn’t burn the gas, you didn’t burn the gas. “Typical driving conditions” apply to ICE engines too. If I constantly gun the engine on my SUV, I’d be surprised if I got even half the pathetic mileage I already do. Having the Volt system means you don’t have to fill up as often, given certain driving habits. This is no different than reasonable, non-aggresive driving vs. aggressive wasteful driving of any other vehicle. People are just bent out of shape because the advantages of the Volt are SO dramatic, it appears to be a gimmick. The reality is, if you drive less than 40 miles a day, you WILL get 230MPG or better because the metric IS gasoline consumption!
    If you want to complain about the MPG metric, complain about the MPG metric. I would wholeheartedly agree with changing to a miles/net kWh measure for both gasoline and EVs. But while I’m wishing for ponies, we should convert to the metric system too. Good luck getting that past the uneducated and traditionalists morons.
    But honestly, don’t lambaste GM for making reasonable use assumptions based on ratings and statistics they are REQUIRED BY LAW to compile when it’s already done for EVERY other vehicle on the road.

  121. Anonymous

    Here’s my issue. It sounds like this car is clearly designed for people who drive less than 40 miles a day…primarily people who live in or near a city, for example. Great!…or is it?
    Does no one else see the problem with that? Most people who live in or near a city park on the street, or in a large shared garage. Where are they going to plug in the car for the several hours that it needs to charge every day. Will every Volt come with a 100ft extension cord?

  122. aratina cage

    Thank you for this. The EPA’s recent update of it’s mileage standard looks like it is in need of updating again. As a non-plugin-hybrid owner, I instantly felt the 230 mpg estimate could be dishonest (much like the old EPA estimates for non-plugin hypbrids were). Many working parts of the car drain non-plugin-hybrid batteries considerably, including A/C and heating, windshield blowers, terrain, tire characteristics, and outside wind; I don’t think that will be changing for plugin hybrids. Even if the Volt is a great car in terms of fuel savings and pollution standards, I think this 230 mpg estimate could hurt sales (and GM’s name) substantially in the beginning if it proves to be wildly inaccurate.
    Anyone interested in comparing EPA fuel mileage estimates to real mpg averages from owners of existing U.S. vehicle models can browse around at (you may even be able to see how a model rates in your state by clicking on “View Individual Estimates”).

  123. Tom

    $.057/kwh? How nice… we pay around $.16/kwh in the Northeast.
    Electric cars only make sense if you have a cheap source of clean electricity, maybe nuclear or wind. They can improve the grid’s efficiency by charging during times of peak supply and low demand, so that’s a bonus. These things just might work.
    Of course there’s a simpler solution — walk to work!

  124. Bob

    Tell it to the EPA, clown.
    “The method that GM used to produce that mileage figure is extremely dishonest and completely uninformative.”
    GM is just using the published methodology that the EPA is going to use for this new class of plug-in hybrid vehicle.
    Here’s a news flash – the old EPA methodology for regular cars wasn’t totally accurate, or informative, either.

  125. JODY

    Just when I was warming up to some of their new vehicles, GM goes and pulls a high one like this.
    Nothing has changed, there fore I will never EVER trust GM for sure now !!!

  126. Hank

    Why GM isn’t being honest
    “The honest way to describe it is to say “Up to 40 miles without consuming gas, and then 50 miles per gallon”. That’s not so horribly difficult, now is it?”
    GM can’t say this because it’s the same as saying “the Volt has the same MPG as the Prius, but saves you less than a gallon of gas a day – and for only $18K more”.
    The average driver will never breakeven on the Volt’s cost, so instead GM is hiding this info by leading people to believe it’s many times more efficient than competing cars (never mind MPG is nonlinear and most people don’t realize it, but that’s another topic altogether).

  127. Jim Firenze

    “The honest way to describe it is to say “Up to 40 miles without consuming gas, and then 50 miles per gallon”. That’s not so horribly difficult, now is it?”
    Hmmm, no-one bothered to point out YOUR bad math, which only goes to show how the whole issue is obfuscated.
    Total Range: ~300 miles
    Electric only Range: ~40 miles
    Fuel Tank Capacity: 12 gallons
    This means the range is 260 miles when it’s purely running on gas. This means that when it’s gas-powered it’s getting ~21mpg. Not 50. Which means YOUR commute would net you ~126mpg
    Apparently, it IS difficult for you. ;o)

  128. Eddie

    This is all very stupid.
    Just tell me, man, how far the effing car will go with a fully-charged battery and a full tank. No math, no mpg gibberish.
    Just tell me: fully-charged battery, full tank of gas — how many miles can I go? And don’t be cute and ask where I’m starting from.

  129. BKU

    OK… (For post #149) If I understand right the volt has a range of 300 miles on 12 gallons of gas which is 25 mpg. My Prius averages about 500 miles on 11.9 gallons of gas which is 42 mpg. This tells you nothing about how the two cars compare! Each individual who is considering this car will have to do THEIR own math based on THEIR expected usage pattern to figure out THEIR expected cost! No one size fits all calcualtion will tell the story!

  130. Michele

    this is not surprising considering that they FLAT OUT LIE about the mpg of ALL chevy models. i’ll stick with honda and toyota, thank you very much…

  131. sasa

    Tell it to the EPA, clown.
    “The method that GM used to produce that mileage figure is extremely dishonest and completely uninformative.”
    GM is just using the published methodology that the EPA is going to use for this new class of plug-in hybrid vehicle.
    Here’s a news flash – the old EPA methodology for regular cars wasn’t totally accurate, or informative, either.

  132. so4pro

    Here’s my issue. It sounds like this car is clearly designed for people who drive less than 40 miles a day…primarily people who live in or near a city, for example. Great!…or is it?
    Does no one else see the problem with that? Most people who live in or near a city park on the street, or in a large shared garage. Where are they going to plug in the car for the several hours that it needs to charge every day. Will every Volt come with a 100ft extension cord?


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