Chevrolet Volt Gets 230 MPG City Fuel Economy Rating

By Chris Haak


230Earlier this morning, GM finally revealed what the “230” viral marketing campaign has been all about for the past few weeks.  As many suspected, the number represents the fuel economy of the upcoming range-extended electric Chevrolet Volt – specifically, the city fuel economy.  The highway figure will be significantly lower, but still better than nearly every car on the road.

The figure is based on a new methodology developed by the EPA specifically for plug-in electric vehicles that assumes more [electric] city driving than the standard EPA fuel-economy tests.  From GM’s press release:

Under the new methodology being developed, EPA weights plug-in electric vehicles as traveling more city miles than highway miles on only electricity. The EPA methodology uses kilowatt hours per 100 miles traveled to define the electrical efficiency of plug-ins. Applying EPA’s methodology, GM expects the Volt to consume as little as 25 kilowatt hours per 100 miles in city driving. At the U.S. average cost of electricity (approximately 11 cents per kWh), a typical Volt driver would pay about $2.75 for electricity to travel 100 miles, or less than 3 cents per mile.

GM had been lobbying the EPA to devise a special test for plug-in range-extended EVs that “give them credit” (my words, not GM’s) for the fact that some 70% of daily commutes are less than 40 miles roundtrip, so the Volt theoretically could use nearly zero gasoline during normal driving, so a little number crunching/playing on the EPA’s part is not surprising.

2011 Chevrolet Volt Production Show CarThe 230 miles per gallon number certainly is eye-popping.  While details of the test procedures were not released for public scrutiny, reported that Mike Duoba, a scientist at Argonne National Laboratory, was able to nearly duplicate the 230 mpg number in his tests:

Mike Duoba from Argonne National Lab devised a method to determine the MPG of an EREV; first the car is driven from a full battery until it reaches charge-sustaining mode, then one more cycle is driven. If we use the highway schedule, the first 40 miles are electric.  One more cycle is 11 more miles. If the Volt gets 50 MPG in charge sustaining mode, it will use .22 gallons of gas for that 11 miles.  Thus 51 miles/.22 gallons = 231.8 MPG.

Unsurprisingly, the more miles driven between the Volt’s overnight charges, the poorer the fuel economy number will be.  Driving the car across the country won’t get anywhere near 230 miles per gallon, but driving it across town might actually get an infinite mileage number because no gasoline would be used.

The 2010 Toyota Prius is the current mileage champ (at least among mass-production cars available in the US), and it’s rated at 48 mpg city/51 mpg highway.  Depending on the distance of the EPA highway cycle test for the Volt, its highway rating is likely to be closer to the Prius’ 51 mpg number (it has a similarly aerodynamic shape and will have a 1.4 liter engine vs. the Prius’ 1.8 liter, but may weigh more with GM’s traditional hefty engineering and additional battery capacity).

This number is certain to get GM some positive attention when the company is desperately trying to spruce up its environmental image in the eyes of the public (and likely its government owners).  The idea of driving a car and rarely needing to refuel it, not to mention paying a fraction of the price of gasoline for electricity (the Prius at 50 mpg costs about 20 cents per mile for gasoline assuming $2.50 per gallon, while the Volt is quoted at less than 3 cents per mile).

Of course, Toyota is not sitting idly by and allowing GM to steal its spotlight.  A plug-in Prius is coming in a few years, and GM has the pesky problem of selling buyers on its $40,000 230-mpg car when Toyota is offering a $23,000 50-mpg car.  Tax incentives will help GM bring the price difference down to about $10,000, but still, $10,000 buys a lot of miles’ worth of gasoline at 50 miles per gallon and $2.50 per gallon (200,000 miles).

I have a suspicion that these are just the opening salvos in the new decade’s fuel-economy wars.  The horsepower war is, sadly, winding down.

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Author: Chris Haak

Chris is Autosavant's Managing Editor. He has a lifelong love of everything automotive, having grown up as the son of a car dealer. A married father of two sons, Chris is also in the process of indoctrinating them into the world of cars and trucks.

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  1. Despite this achievement GM has been denied 3 times in its applications to the USDOT (Transportation) for alternate energy vehicle development loans.

    In a filing with the USDoTreasury last week, GM stated that if it doesn’t get the USDOT loans GM’s alternate energy development will be surpassed by that of its competitors in short order.

    Does anyone else sense that there will be a huge rebate program funded by Washington to get consumers into Washington’s new baby [Volt] come November 2010, with funding coming from either a Federal Highway use tax or gasoline tax?

  2. Chevy needs the Volt to supplant the Prius as the fashionable green accessory for Hollywood. Otherwise, we will probably see the Volt go the way of the EV1.

  3. Phenomenal rating, but will it get GM more buyers for the Volt? I don’t think so. I think most people who want to spend this sort of money will research the car heavily and know it’s strengths and limitations clearly.

    That number sure will look good in the ads, though.

  4. Some think then the Volt could be eclipsed by the upcoming Nissan Leaf but we have to wait and see how the Leaf will do in a rural area. And they claim 367 mpg

    Also, a rumor mentionned then Fiat and Chrysler CEO Sergio Marchionne gived the green light for a car based on the 200C concept-car not in the same league as the Volt and the Leaf, it might be interesting to check an eye on it

  5. Rating an electric car this way is misleading, if not virtually meaningless. I know there is an obsession with making measurements as simple and understandable as possible, but in the case of a car like this you just can’t accurately portray its efficiency with a single number.

    I think it should have at least two basic ratings: energy consumption in electric mode using some standard usage guidelines (kind of like the “average cost to use per year” energy guide ratings on water heaters), and a separate rating JUST with the gas engine (which will all know will be pretty ordinary). Make people do a little math in their head so they understand what they’re getting. Rolling it into a standard mpg rating just misleads people, and GM bragging about 230mpg is setting up Volt customers for absolute disappointment.

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