(February 17, 2011) WASHINGTON, D.C. — With the arrival of the first widely available plug-in vehicles, model year 2011 boasts the most diverse car offerings ever in terms of technologies and fuels.

This week greenercars.org, the American Council for an Energy-Efficient Economy released its 14th annual environmental ratings for the model year showing how they all stack up. The result? Some newcomers — including an electric vehicle and a plug-in electric hybrid — did well, while several of the regulars held their ground.

Surprising perhaps, but the much-honored Chevrolet Volt managed only a 13th-place finish, just behind the Mazda2. Both had scores of 48.

Honda Civic GX

This year’s ratings reveal a face-off among plug-ins, gasoline hybrids, diesels, natural gas vehicles, and ever-improving “conventional” gasoline vehicles. For the 8th year, the Honda Civic GX wins top honors, notwithstanding changes to Green Book rating methods that boosted other technologies.

But below the top spot, the “Greenest” list sees a shake-up: the all-electric Nissan Leaf placed second, followed by the gasoline-powered Smart Fortwo. Hybrids took the next three spots, followed closely by Ford’s new Fiesta SFE (Super Fuel Economy) and the Chevrolet Cruze Eco. Also notable on this year’s list is the Hyundai Elantra, with a 4 mile-per-gallon jump in fuel economy over the 2010 model. Rounding out the “Greenest” are the Mazda 2 and the much-touted Chevrolet Volt “extended-range EV,” which slipped into the 12th and 13th spots.

All told, six new models pushed out entries on last year’s list.

Honda vehicles again were recognized as some of the greenest in the industry. In addition to the natural gas-powered Civic GX in first place for the eighth time, the Honda Civic Hybrid was fifth and the Honda Insight sixth. The CR-Z Sport Hybrid coupe and Odyssey minivan were also named as the "greenest vehicles" within their respective classes.

This is the 11th year in a row that a Honda vehicle has received the number one ranking and the 13th straight year that multiple Honda vehicles have been named in the top 12.

The strong showing of conventional vehicles in the top 13 is a testament to how serious manufacturers have gotten about recasting these vehicles as fuel-sippers with transmission refinements, weight savings, and sophisticated internal combustion engines.

“We’re seeing an increasing number of highly efficient gasoline options from both foreign and domestic automakers along with the first electric vehicles. Ford introduced the Fiesta this year and Chevrolet debuted the Cruze, both of which do exceedingly well in our ratings,” said ACEEE vehicle analyst Shruti Vaidyanathan.

Regarding plug-in vehicles, ACEEE Transportation Director Therese Langer noted: “Vehicles running on electricity emit nothing from the tailpipe, but their ‘upstream’ emissions can be substantial, depending on where they’re charged. As U.S. power generation becomes cleaner, these vehicles’ scores will rise.”

The Green Book methodology update also incorporates emissions associated with battery manufacture and disposal in a manner that reflects material content, drawing from Argonne National Lab’s GREET model. Hybrids lose a couple of points on their Green Scores as a result and this year capture only three of the top 12 spots. Once again diesels fall just short of the Greenest list.

The greenercars.org web site also identifies a selection of top, widely-available models in each vehicle class. This “Greener Choices” list includes trucks and SUVs such as the Hyundai Tucson, Chevrolet Equinox, GMC Canyon, and the Ford F-150 (FFV). Cars such as the Honda CR-Z and Hyundai Sonata top their respective classes. As the list demonstrates, consumers can make “greener choices” whatever their vehicle needs may be.

The “Meanest” list this year — the lowest scoring vehicles — is populated largely by heavy trucks and SUVs, a marked change from the numerous European sports cars that dominated last year’s list. Nevertheless, the Bugatti Veyron tops the list this year with a Green Score of 19.

Greenest Vehicles of 2011

Meanest Vehicles for the Environment in 2011