Chevy Volt Barely Makes 2011 List of Greenest Vehicles

By Brad Berman · February 17, 2011

The American Council for an Energy Efficient Economy’s Green Book is the bible of environmental rankings for cars and trucks. And the 2011 issue, the 14th annual edition, just hit the streets. “This is the most exciting Green Book in a decade for me, because there are so many vehicles in the running,” said Therese Langer, ACEEE’s Transportation Director, in an interview with PluginCars.com. The non-profit uses an exacting methodology for calculating the environmental impact of all cars and trucks.

Despite new competition from electric vehicles, such as the all-electric Nissan LEAF and the Chevy Volt plug-in hybrid, the winner for the 8th consecutive year is the Honda Civic GX, which runs on compressed natural gas. “The Chevy Volt came very close to not making the list,” said Shruti Vaidyanathan, ACEEE Vehicle analyst. The first negative mark against the Volt in ACEEE’s methodology is the weight, which provides an indication of how much energy went into producing the vehicle. The Volt weighs about 500 pounds more than the Nissan LEAF or Toyota Prius.

The non-profit also took a hard look at the Volt's operation on the road. “The Volt running on gasoline doesn’t have terribly impressive fuel economy. It’s rated at 35 mpg in the city and 40 highway,” said Therese Langer, ACEEE’s Transportation Director. “If you think of it as a vehicle that is roughly two-thirds electric and one-third gasoline, as an electric vehicle it does pretty well, but not quite as well as the LEAF.”

The "two-thirds EV and one-third gas" approach stems from data about typical driving patterns of American drivers, as used by the Society of Automotive Engineers and the Environmental Protection Agency.

“As a gasoline vehicle, the Volt does okay, but there are a whole lot of gasoline vehicles that beat it out," said Langer. "So when you take the fact of those two things together, it comes out about where you think.”

While the Civic GX took top honors, the Nissan LEAF was an incredibly close second place—coming within 2 percent of ACEEE’s calculations for environmental impact. When you consider that ACEEE uses a national average for the green-ness electricity generation, the Nissan LEAF becomes the clear winner in parts of the country where electricity is made mostly from renewable sources.

The diversity of auto technologies and drivetrains is striking in this year’s Green Book. The top four slots are made up of a vehicle running on compressed natural gas, an EV, a small internal combustion engine vehicle, the Smart ForTwo, and the Toyota Prius, a conventional hybrid.

The Smart ForTwo leapt ahead of the Prius and the Civic Hybrid because ACEEE shifted its methodology to utilize version 2.7 of the Argonne National Labs GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) Model. In prior years, the battery of a hybrid or electric car was scored for weight just like any other component of the car. But with the new GREET methodology, batteries are considered to have a greater environmental impact, because of the energy and other resources required to manufacture the batteries. As a result, hybrids took a hit in 2011.

Nonetheless, the Prius, Honda Civic Hybrid, and Honda Insight ranked fourth, fifth and sixth respectively. The rest of the list was made up of small internal combustion cars: Ford Fiesta SFE, Chevy Cruze Eco, Hyundai Elantra, Mini Cooper and Toyota Yaris. And taking the final spot in ACEEE’s Top 12 Greenest Cars is the Chevy Volt.

Update 2/17/11: On Feb. 16, ACEEE corrected two mistakes in its calculations. The 2011 Toyota Prius uses a 1.8-liter engine, not a 2.0-liter as previously noted. More importantly, the Chevy Volt is certified as a Bin 4 / ULEV II, not a PZEV. As a result, the Volt drops to 13 in the list, and is bypassed by the Mazda 2.

Other vehicles that nearly match the environmental score of the Volt, but that did not make the top 12, are clean diesel versions of the Volkswagen Golf, Volkswagen Jetta and Audi A3; the hybrid Honda CR-Z; and the gas-powered Mazda2.

When asked how much longer the Civic GX could maintain its top position, ACEEE researchers pondered that the competition is going to get even tougher next year. Vaidyanathan pointed to the upcoming Smart ED (Electric Drive), which already scores well as a gasoline car; and the plug-in Prius, which already scores well as a conventional hybrid without plug-in capability. By running on electricity instead of gasoline, both of these cars have a chance of taking the lead position in 2012.

The 8th consecutive victory for the Honda Civic GX hopefully will draw attention to the model, which is the only compressed natural gas vehicle in U.S. showrooms. Last year, Elmer Hardey, Honda’s senior manager of alternative vehicles, told HybridCars.com that the Honda Civic GX will become an even more important option for the upcoming 2012 redesigned Civic. “With all the activity in the environmental vehicle space, we’re anticipating growth in sales of CNG vehicles, not only in California but nationwide,” said Hardey.