Electric Cars: Leaf Beats Volt in New Ranking

Last Updated Feb 17, 2011 8:39 AM EST

A question we've been asking: How Green are Electric Cars? got one possible answer today. In its 14th annual listing of greenest cars, the American Council for an Energy Efficient Economy ranked the all-electric Nissan Leaf second but the Chevrolet Volt, which has an auxiliary gasoline engine, thirteenth. . The winner was the Honda Civic GX, which runs on natural gas.

The relatively lousy ranking for the Volt results from the ACEEE's "lifestyle analysis" methodology, which attempts to measure all environmental impacts, from the manufacture of a vehicle to its energy use and pollution while it is driven, to its eventual disposal. EPA mileage ratings and emissions classifications are used to rate energy consumption, air pollution impact and greenhouse gases, which contribute to global warming. In the case of electric vehicles, allowance is made for pollution from power plants charging the battery. Those factors, but primarily the very low air pollution, is what put the Civic GX on top of the list for the eighth straight year.

The advantage that helped make the Chevy Volt (at left) the North American Car of the Year works against it here. When the Volt runs out of battery charge, it switches to an auxiliary gas engine to generate power and extend its range to about 300 miles. "Even though we assumed the Volt would run on electric power 60 % of the time, when it is using gas, its mileage (35 mpg city, 40 highway) is well below several other cars," ACCEEE vehicle analyst Shruti Vaidyanathan explained in an interview. She added that greater weight (3870 lb for the Volt vs. 3354 lb for the Leaf ) worked against the Volt since more weight in the rankings is equated with more materials and more environmental impact from manufacturing.

While hybrids predictably ranked high on the list (Toyota Prius fourth, Honda Civic hybrid fifth), ACEEE noted that high-mileage, gas-only small cars also broke into the top ten this year. That includes the Ford Fiesta SFE, Chevrolet Cruze Eco and new Hyundai Elantra. (For more on these cars, see Gas Mileage: 40 MPG is the new 30).

For car shoppers who care about their environmental impact but are looking beyond just the highest-mileage, lowest-polluting choice, ACEEE offers a helpful list of vehicles in various categories that score well in their ratings. Here are three of those suggestions:

Audi A3 Diesels don't score at the top of the ACEEE list because of their emissions of smog-causing nitrogen oxides. But the small hatchback A3 gets a 48 in the green score ratings where the winner scored 54. The A3 is praised by reviewers for its fun performance, top safety rating and sporty exterior styling. The diesel version -- rated at 30 mpg in city driving, 42 mpg highway -- was named green car of the year for 2010 by Green Car Journal, which has different methodology than the ACEEE. The base model 2011 A3 TDI diesel lists for $29,950

Hyundai Sonata Among mid-size sedans, Hyundai positioned the Sonata to be mileage leader (22mpg city, 35 highway) by offering only a four-cylinder engine plus a hybrid version. The Sonata scores 43 in the green car ratings. Reviewers like its sharp styling and reasonable price, with the base model starting at $19,195.

Chevrolet Equinox Among crossover SUVs, the Equinox gets among the better mileage ratings (22 mpg city, 32 highway). Its green list score is 41. Reviewers note that the strong-selling Equinox is bigger than competitors like the Honda CR-V but gets better gas mileage. The base model starts at $22,745.

As manufacturers work to meet the federal government's stricter mileage standards by 2016, you will have more relatively green choices every year.

Photos courtesy of the manufacturers

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    Jerry Edgerton, author of Car Shopping Made Easy, has been covering the car beat since Detroit companies dominated the U.S. market. The former car columnist for Money magazine and Washington correspondent for Business Week, Edgerton specializes in finding the best deals on wheels and offering advice on making your car last.