Tuesday, August 11, 2009

Rating Hybrid's Miles per Gallon

Efficiency window sticker for Mini E

G.M. announces that the Chevy Volt will get 230 miles per gallon in city driving. Bill Vlasic of The New York Times reports:
The rating is based on methodology drafted by the Environmental Protection Agency, and most other automakers have not revealed the mileage for the electric cars. Nissan, however, announced last week that its all-electric vehicle, the Leaf, which comes out in late 2010, would get 367 m.p.g., using the same E.P.A. standards.
But readers raise some valid points in the article's comment section about mileage ratings and the true environmental impact of hybrid and electric cars:
As near as I can tell, this is essentially an electric car. Its gasoline consumption is projected to be very low. Where are the mileage figures that factor in the electricity consumption? The Volt may indeed be a remarkably efficient vehicle. But when fuel is burned to generate electricity, and over half of it is lost in transmission to the customer, and then it's used to charge this car's batteries, there's going to be more than one gallon of fuel consumed when driving this car 230 miles.
HybridCars has a post that reveals just how complicated it can be to come up with an accurate rating system that consumers can understand:

When plug-in cars hit the US market in the next year or two, consumers will need a lot of help deciphering the efficiency figures of vehicles that carry electric fuel by the kilowatt hour rather than liquid fuel by the gallon. Nissan’s upcoming yet-to-be-named electric car, according to some tests, will get 367 miles per gallon. The Tesla Roadster is reported to get 135 miles per gallon. And the Chevy Volt plug-in hybrid…that depends.

If the EPA uses tests designed for electric cars to evaluate the Chevy Volt, the ratings could exceed 100 mpg. But if the government agency classifies the Volt as a hybrid and tests it as such, the EPA rating would drop to about 50 mpg. The difference could mean success or failure in the marketplace. Corporate Average Fuel Efficiency and sticker numbers for plug-in hybrids, which use gasoline and electricity in various degrees and ways depending on the specific vehicles design, have not yet been determined.


  1. This is great news for the environment. This is great for releasing us from our dependence on Middle East and African oil. Which will translate to better security.

  2. Well, I'm not sure it's great news for the environment. It may help us be less dependent on foreign oil and more dependent on domestic energy sources that also harm the environment. It does seem like it would help our foreign policy, but I'd welcome any insight into just how much it helps the environment. For example, the hybrid SUVs and huge sedans I'm seeing probably use more energy than a regular old small car.

  3. I should add that I'm not against hybrid or electric cars. I'd just like us to be realistic about how much they're helping us.

  4. If we could get to national self-sufficiency in oil consumption, so that we no longer cared enough about the security situation in the Persian Gulf to send our own armed forces there and we could ignore tinhorn Venezuelan dictators, we could save about a zillion dollars a year in military costs.

    Then we could pay down the national debt, *and* pay for a few more EPA cleanups (i.e. Buick City), *and* fund the installation of CO2 liquifaction facilities for the U.S.'s coal power plants, *and* build a new generation of extra-safe nuclear power plants, *and* fund a permanent solution for the national nuclear waste issue.

    The national security aspects of imported oil are this country's #1 environmental issue.

  5. And all it will take to make that laudable goal a reality is to circumvent the power that the oil industry has over Washington.

  6. And I fear that while more fuel efficient vehicles will obviously help us get off foreign oil to a certain degree, we are not taking the big steps that will help us achieve that goal.

  7. The thing about the Volt is that it really is a step in the right direction. It's an electric car that uses another energy source (in this case gas) to extend its range. The gas engine is connected to a generator that drives electric motors.

    Given this, the next logical step is replacing the gas engine with some other non-fossil fuel-based power source. Or the batteries get better. Either way, it is a positive step forward for the environment. Especially once the electricity you charge it with overnight no longer comes from coal plants.

  8. After the bankruptcy GM had to come out with a game changer.

  9. Crank up some nuclear power. It's really the cleanest alternative out there. Unfortunately Gasoline is one of the most efficient sources of stored energy, and that's why it still fuels cars. Electric cars just pull their power off the grid and store it in batteries. So when you plug that electric car in to the wall, that energy is probably coming from something way worse than gasoline.... Coal! Now when you look at at available energy per gram of fuel. Nuclear has everything else beat hands down. Once people can disassociate "nuclear" from "bomb" we will be on our way. Europe uses a lot of nuclear power, with France getting something like 80% of their electric needs from nuclear. Reactors are safe, especially newer designs such as the "Bed of Pebbles" reactor. Our nuclear industry is currently based on 40+ year old technology. Let's commission some new power plants. The benefits include:
    1. less dependence on foreign oil.
    2. Lots of cheap electricity to fuel electric cars.
    3. Get rid of stockpiled nuclear weapons by burning the weapons grade Plutonium, and Uranium as Mixed Oxide fuel. We must have a damn near endless source of energy sitting around in the pits of decommissioned weapons.

  10. I largely agree with LarryPrune. Until we catch up in terms of energy production and move to mostly nuclear energy, "green" cars don't seem that helpful.

    It can also be misleading when talking about cars that are essentially EVs (I'm including the Volt under that) to refer to MPG, since gasoline plays such a small part in the equation. I'd be interested to see how the M/KWH on the Volt stack up to those of the Tesla and the Leaf.

    Thought you all would be interested in this video touching on some of the top criticisms and praises of the Volt, as well:



Thanks for commenting.