And the greenest car is?

It's been twelve years since an electric car was ranked the greenest car in the U.S. but Mitsubishi Motor's new i-MIEV has finally unseated the Honda Civic Natural Gas vehicle after its eight-year stint at the top.

The Council for an Energy-Efficient Economy (ACEEE; Washington, DC) recently released its Council for an Energy-Efficient Economy released its 14^th annual comprehensive environmental rankings for 2012 where vehicles are analyzed on the basis of a "Green Score:" a singular measure that incorporates unhealthy tailpipe emissions, fuel consumption, and emissions of gases that contribute to climate change.

All-electric Mitsubishi car judged the greenest in the U.S.

With a combined city and highway fuel economy of 112 miles per gallon equivalent, the i-MIEV outpaces all other vehicles currently sold in United States. "Even taking into account the emissions generated from the electricity used to power the i-MIEV, it still handily outscores other vehicles on the market today," says ACEEE lead vehicle analyst Shruti Vaidyanathan.

The Honda Civic Natural Gas, despite its improved fuel economy this year, appears in second place, tied with the electric Nissan Leaf. Rounding out the top six are the hybrid Toyota Prius, the hybrid Honda Insight, and the gasoline engine Smart ForTwo. This year, hybrids dominate the "Greenest" list occupying half of all spots. Highly efficient conventional gasoline vehicles also continue to have a presence on the "Greenest" list, claiming three of the top twelve spots.

"It's increasingly obvious that automakers are fully invested in providing consumers with the widest possible array of vehicle choices. Earning a spot on the "Greenest" list is proving to be a real challenge for automakers given the variety of vehicle technologies on the market and the proliferation of highly efficient conventional vehicles. Just using the latest technology does not guarantee a top spot," says Vaidyanathan. This year saw the arrival of a number of new hybrid options for drivers from Hyundai, Kia, and Infiniti, but none broke into the top twelve.

This year, a number of updates were made to the Green Book methodology to more accurately estimate the environmental impacts of vehicles. These include improved emissions estimates for the vehicle manufacturing process, changes reflecting current natural gas extraction practices, and consideration of upcoming shifts in the generation mix for the electricity used to power electric cars.

The ACEEE also identifies top, widely-available models in each vehicle class. This "Greener Choices" list includes trucks and SUVs such as the Chevrolet Equinox, GMC Canyon, Honda Odyssey, and the Ford F-150 (FFV). Cars such as the Chevrolet Sonic-5 and Hyundai Sonata top their respective classes. As the list demonstrates, consumers can make "greener choices" whatever their vehicle needs may be. Domestic U.S. manufacturers claimed five of the twelve spots.

The meanest?

The "Meanest" list this year sees a number of heavier light-duty vehicles, pushing out European sports cars as the highest emitters. The dirtiest vehicles for 2012 are the twin Chevrolet G3500 Express and GMC G3500 Savana cargo vans, followed by the Ford E-350 Wagon and the Bugatti Veyron sports car.-[email protected]