by: Bengt Halvorson | AOL Autos

    General Motors’ upcoming Volt plug-in gasoline-electric hybrid has already grabbed plenty of buzz over the past couple of years. But Volt mania reached a fever pitch this summer when General Motors announced that it would achieve 230 miles per gallon.

    Later the same week, Nissan revealed that its upcoming Leaf electric vehicle would achieve 367 mpg.

    Before you go put your money down, beware—neither of those two numbers are official U.S. Environmental Protection Agency (EPA) fuel economy estimates. The EPA hasn’t yet formalized any method of testing or rating plug-in hybrid vehicles or a new generation of electric vehicles, and you won’t find either of those numbers in the EPA’s annual Fuel Economy Guide or on window stickers because they’re still prototypes.

    Turns out both of these triple-digit numbers rely on optimistic methodologies that are favorable for the respective vehicles but not or easily applied to other types of vehicles or compared to present-day fuel economy figures.

    The recent claims remind John DeCicco, a transportation and energy issues expert, of the time just after the 1973 oil crisis and before the first official EPA fuel economy ratings were available, in 1975. Some manufacturers around at that time advertised their vehicles with “outlandish mileage claims,” recalled DeCicco, also a senior lecturer on energy and climate policy at the University of Michigan. “We’ve again got a situation where manufacturers will spin the number to look good,” he said.

    Looking at the 230-mpg figure, there’s no way of saying simply that the Volt would use less than a quarter of the fuel of a 50-mpg Toyota Prius to go the same distance.

    It is however fair to say that in typical driving a 50-mpg Prius will go twice as far on a gallon of gas as a 2010 Toyota Corolla XRS, rated at 25 mpg. Such comparisons are fair game for any light vehicle that’s officially on sale in the U.S. Every one carries EPA fuel economy ratings, which are designed to give prospective owners an idea of relative fuel cost in real-world driving as well as a way of comparing various models on equal ground.

    The ratings are listed in the EPA’s annual Fuel Economy Guide, at fueleconomy.gov, or on the window sticker of any new vehicle; they’re also used in figuring an automaker’s corporate average fuel economy (CAFE) and in assessing a gas-guzzler tax on some vehicles. They’ve become an important way in which shoppers can easily compare one vehicle to another, and it assures a level playing field because of rigorous testing.

    Running on fumes—on a treadmill

    In the tests, vehicles are driven under controlled conditions in a laboratory using a dynamometer—described by the EPA as a treadmill for cars. The dynamometer accounts for things like drag and air resistance, and temperature, humidity, and even barometric pressure are all accounted for.

    Nearly all vehicles are tested by the manufacturers according to strict stipulations, with full test results sent to the EPA; then the EPA confirms between 10 and 15 percent of the results annually at its National Vehicles and Fuel Emission Laboratory in Ann Arbor, Michigan. According to Linc Wehrly, the manager of light-duty vehicle testing at the laboratory, vehicles are chosen for confirmation either randomly, or because they have new technology, are a new entrant in the market, or boast especially high or low fuel economy.

    The two basic test cycles, City and Highway, have been run in much the same way for decades. The City test represents low-speed and stop-and-go driving, with a cold start, a top speed of 56 mph, and an average of just 20 mph, with 23 stops over 11 miles. Maximum acceleration is an extremely gentle 3.3 mph/second though. The Highway test, is intended to replicate free-flow highway driving, with an average speed of 48 mph and a top speed of 60 mph over 10 miles, with no stops and no idling.

    Over the years the two sets of test numbers have been adjusted a couple of times to better match the numbers seen in real-world driving. Most recently, in 2008, along with a new fuel economy label for new cars, three new tests were added—High Speed, AC, and Cold Temp—to bring City and Highway estimates more in line with what a high percentages of drivers could obtain in real-world driving. Pretty self-explanatory by name, the three tests factor in more realistic rush-hour traffic congestion and speeds up to 80 mph; a test with the air conditioning on (it’s turned off for the others); and a run of the City test cycle at 20 degrees Fahrenheit.

    At first hybrid owners cried foul because the new system applied a more severe correction to vehicles getting higher mpg figures.

    Regulators decided to use the new five-cycle tests “to recognize that there are different effects in different types of vehicles,” confirmed Michael Love, the company’s national regulatory affairs manager, who explained that the new fuel economy tests will have slightly more impact lower-power vehicles and smaller-displacement engines suffering bigger hits because of the AC test, for instance.

    From 2008 until 2011, as the new tests are being phased in, manufacturers can choose from performing all five of the new tests to yield revised City and Highway figures, or adjust their figures from existing tests using a set of equations. From the 2011 model year on, manufacturers will be required to run all five test cycles, so don’t be surprised if the numbers change a bit next year, too. Most major automakers have phased in the new method for some but not all of its vehicles this year.

    “The biggest hurdle was telling consumers that there was no change in the technology of the vehicle” despite the different numbers for the last round of changes in 2008, said Charles Territo, communications director for the Auto Alliance, an association representing eleven different automakers.

    “The regulations try to find a good middle ground,” assessed Territo. There’s no question that there are certain vehicles that fare better than others in the test, according to Territo, but the tests and ratings assure that overall vehicles are regulated to the same point.

    Ramping up for major change

    With a host of plug-in hybrids, electric vehicles (EVs), and extended-range EVs all expected to go on sale over the next several years, the agency needs to move quickly to put a framework in place for fairly rating these vehicles.

    “That GM ad put the heat on them,” said Love.

    The EPA has in the past rated EVs (such as General Motors’ EV1, which sold in the late ’90s) in terms of kilowatt-hours per 100 miles, which typically yields a double-digit number somewhat like miles per gallon.

    Most of the rest of the world is accustomed to comparing vehicles by consumption (lower is better, of course). Fueleconomy.gov already allows users to switch to a consumption-based figure, in gallons per 100 miles, if that helps them more easily compare vehicles.

    Auto Alliance’s Territo says that a consumption standard is certainly on the table for new standards, but with new units like kilowatt-hours thrown into the mix, it’s not likely. “For years we’ve gone by mpg and that’s what consumers understand,” he said.

    Indeed, the EPA has already been listing some alternative-fuel vehicles, like the natural-gas-powered Honda Civic GX, in gasoline-equivalent mpg.

    Currently the EPA is working with manufacturers, the Society of Automotive Engineers (SAE), the State of California, the Department of Energy (DOE), and other groups to form a new standard for estimating and labeling fuel economy for vehicles with more than one energy source.

    Labeling vehicles with two different efficiency ratings—which shoppers would weigh differently depending on how they intend to use a vehicle—is an option, but it would be tremendously confusing to most.

    “There is an unambiguous way of doing this,” and produce a new method that would be fair for all vehicles, argues DeCicco, who thinks that the best, most objective metric would be energy (possibly in BTUs) per mile.

    Cost per mile would of course make the most sense to economically minded buyers, but it would become confusing and difficult to compare from year to year because of unstable energy prices.

    And the challenge for plug-ins would be making it scientific, fair, and rational, no matter what the vehicle. For instance, the current fuel economy tests even allow for the state of charge in the batteries of a hybrid vehicle. With the battery packs in plug-in hybrid vehicles and extended-range EVs all different sizes and providing ranges from just 15 or 20 miles up to 60 miles or more in some prototypes, how would that be recognized without penalizing those with shorter range?

    The EPA is working on that, and currently accepting comments on these possibilities. This will all be part of the next round of fuel economy standards phased in beginning in 2012, to yield the federally mandated 35.5-mpg fleet-wide average by 2016.

    GM might have been a little premature in releasing its lofty figure for the Volt, but they highlighted one important point in the process: The next time you go shopping for a new car, those numbers on the window sticker could be very different.

    Read More About the Chevy Volt

    - GM Says Chevy Volt Will Get 230 mpg
    - Chevy Volt Photos
    - Electric Cars Available Now

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    1 - 20 of 51 Comments
    pschmoll43 Oct 28, 2009 7:15 AM
    If we were to go back 100 years and look at the mileage of the early gasoline powered vehicles, then compare that figure to today's figures, I am sure that we would quickly notice the huge strides that have been made in making the gas engine more efficient. Of course those efficiency changes did not really begin to take place until the cost and availability of gas began to come into question. That began in the late 1950's and then more earnestly in the 1970's when availability of gas became more difficult due to political problems. Now, we are beginning a whole new technology as we begin looking at hybrid cars that achieve a portion of the mileage by operating on electricity. I believe that with electrical power, we may be at the stage we were with gas power 100 years ago. That is we are creating electric motors that use large amounts of electricity to operate, and batteries that are in their infancy in terms of efficiency. It would seem to me that it would be important to realize this quickly, and begin as soon as possible to work on creating electric motors that will operate on far less electrical power than they do now, batteries that will store more power in a smaller package, and regenerating systems that are far more efficient than at present. We can't wait 50 years for these efficiencies, or we will be placing the same kind of strain on our power supplies that we have put on oil supplies up until now. If we don't work on these efficiencies, we will quickly find ourselves with a skyrocketing cost of electricity, as well as shortages. On the upside, more efficient electrical motors for automobiles would be only the beginning. That new technology would easily spill over to the use of other electrically operated machinery, even to household appliances, from the largest to the smallest. We must keep in mind that there truly is a limit on the amount of electricity that can be economically produced by dams and power plants, we have to create vehicles and other machinery that can reduce rather than increase the use of power from those outside sources. So, look to the future. Quickly!!
    Report This
    psridgell Oct 11, 2009 9:03 PM
    As usual, the facts are not included. Gasoline is todate the most effiecient fuel by far. I guarantee you will these batteries will use more energy to produce electric fuel, and the batteries will be more dangerous in crashes than gasoline, as well as ground water will be destroyed with millions of these used batteries in landfills and other misused dumping sites.
    Report This
    dpdavid91 Oct 11, 2009 8:14 PM
    I don't understand! But I do know when you plug it in, it's costing and this too needs to be counted as expense. So then what has been accomplished here? dpdavid91@yahoo.com
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    edwardgloria Oct 11, 2009 8:09 PM
    Of course these MPG's can be just numbers - however an inventor did come up with an automobile that prooved to get 300mpg in the early 70's, but the big car manufacturers bought the patent so as to destroy all the drawings and to put the invention to sleep - all in the name of GREED. So.. all these triple digit mileages per gallon for cars isn't new but supressed as is usually done with great inventions so that the big guys interests and profiteering isn't threatened. Everybody knows that cars can be made to run without gas - say using a live cell, ie - a battery that continuously charges itself while being operating and in use. Also cars can be made much simpler mechanically so that common people can fix them. And again cars can be made to last a lifetime. But......................
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    rebelhauling Oct 11, 2009 8:01 PM
    I am going to guess that the actual MPG of the gas engine of the Chevy Volt is about 35 MPG. And that the Electric batteries last about 40 Miles per Charge. throw 230 mpg out the window is a lie.
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    playerbigb Oct 11, 2009 7:58 PM
    rery20, the design does not look anything like the original to improve the aerodynamics to acheive the 40 miles on a charge. Also, there is technology to improve gas mileage in the vehicles, but then you would bitch because of the price of the car with all the technology in it to improve it, so what do you want, a 25K car or a 50K car?
    Report This
    playerbigb Oct 11, 2009 7:55 PM
    Well once again its nice to see the critics know so much more than the engineers do. And when they are wrong for printing this and it shows that the numbers are true, do you think these same morons who wrote this article will have the balls to say they are wrong?! Hell no, they will say "well, we "speculated" and then "fall in love with the vehicles&********** so easy to be a critic, I bet any high school drop out could be one, all you have to do is pick something apart. It takes someone with brains to actually do actual work and design vehicles like this. So you critics just keep picking stuff apart and say you are doing it to improve the products, the real question is, what have YOU done personally to improve humanity, certainly not your little articles criticizing everything. There see, I was a critic, nothing to it.
    Report This
    papachuck63 Oct 11, 2009 7:46 PM
    It's simple! Fill it up and drive it until it quits! Then check the mileage! Why does this car need voodoo math?
    Report This
    rery20 Oct 11, 2009 7:35 PM
    first of all if GM would of kept the first design of the VOLT. Maybe people would be more interested in it. But now it looks like a piece of crap malibu. Why build a cool concept car if your not going to put it in production. I mean who are these idiots? gas mileage this gas mileage that. we all know you people are capable of producing far better gas mileage cars but then the oil companies would loose money aawwww jeezzz like they dont make enough. you people are stupid. Make a car that looks awesome and lasts and everyone will buy it!
    Report This
    brfull3 Oct 11, 2009 7:34 PM
    The Volt wasn't just designed... This is a project that has been in the development stages since long before the Government took over GM. All the remarks about why did they wait until after they declared bankruptcy to releasing this vehicle make no sense. Check the history of this vehicle. It has been at auto shows for the last couple of years. Although the MPG estimate may seem a little of a stretch, it is feasible ************** get close to this mark. Granted, it is going to consume other forms of energy, however, electricity can be generated by many other sources than the local power company. Look into putting solar panels on the roof of your home to generate power not only to recharge a vehicle like this but to also power your entire home.
    Report This
    resortexec Oct 11, 2009 7:30 PM
    What was Detroit thinking by announcing of the Volt with such MPG, even if it gets 125 MPG? The Japanese and other foreign car makers would simply stand by and do nothing? Please. Who is kidding whom?
    Report This
    rbblum Oct 11, 2009 6:57 PM
    Continue to promote and advertise something that is not universally accepted will only backfire . . . and call into question other value concerns . . . such as why a vehicle will likely not last 20 to 25 years.
    Report This
    jfbrow Oct 11, 2009 6:27 PM
    Report This
    mtnbkrbob Oct 11, 2009 6:05 PM
    well people nee to understand the Volt is an ELECTRIC car the 4 cylinder motor is ONLY THERE TO CHARGE THE BATTERY! so they say the car gets 40 miles per charge and one gallon of gas can charge the battery 5-6 times well it would seem that the Volt gets 230-240 miles per gallon? the biggest thing is that society has to remember is ********* AN ELECTRIC VEHICAL IT RUNS ON ELECTRICITY NOT FOSSIL FUEL! ITS ELECTRIC!!
    Report This
    rthate Oct 11, 2009 5:56 PM
    I have wondered on these 'tests' are all that accurate. I mean, what is true on one engine, could it be true on all engines of the same? Its like saying that a 3.2 liter engine can get, say. 25 miles to the gallon, does it mean that another 3.2 can get the same? Oh, as someone once said, 'there's a fool born every minute'. And it does seem so with the public in regaurding these numbers on gallons-per-mile.
    Report This
    jimbo1350 Oct 11, 2009 5:54 PM
    Poster child for the bailout money.
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    kyle76066 Oct 11, 2009 5:36 PM
    My '95 Saturn SL1 with over 271,000 hardly any maintenance miles still easily gets over 40 mpg on the highway. It's no wonder that Gubbernment Moters killed their 1.9 SOHC and then the whole Saturn line. If you trust anyone in Detroit, U.S. Govt., Big Oil, or even Big Pharma.....it's your own fault.
    Report This
    rymndpuckett Oct 11, 2009 5:25 PM
    you could just get a motorcycle and problem solved
    Report This
    eareks Oct 11, 2009 5:24 PM
    GM had wire-car as well. That's" looks great on the paper" as a green energy car, but that's portfolio ONLY to get credit for their initiative. Kissing petroleum based companies continues....If the USA would dominate the world in e/v, we wouldn't be where we are.. It must be reason to do NOTHING, just ordinary people never will know.
    Report This
    eareks Oct 11, 2009 5:24 PM
    GM had wire-car as well. That's" looks great on the paper" as a green energy car, but that's portfolio ONLY to get credit for their initiative. Kissing petroleum based companies continues....If the USA would dominate the world in e/v, we wouldn't be where we are.. It must be reason to do NOTHING, just ordinary people never will know.
    Report This
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    General Motors’ upcoming Chevy Volt plug-in gasoline-electric hybrid has already grabbed plenty of buzz, but Volt mania reached a fever pitch this summer when General Motors announced that it would achieve 230 miles per gallon; however, those MPG numbers aren't official U.S. Environmental Protection Agency (EPA) fuel economy estimates.


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