By Joe Benton

July 24, 2007
A Honda Civic powered by natural gas is the greenest car in America and a Volkswagen diesel-powered Touareg is the meanest vehicle in the land, at least according to the 2007 Green Book which ranks vehicles according to their environmental friendliness.

Consumers looking for green cars and trucks are turning to the Green Book, The Environmental Guide to Cars & Trucks published by the American Council for an Energy-Efficient Economy in growing numbers.

The book helps consumers compare vehicles on the basis of a green score which is a measure that incorporates fuel consumption and air pollution, including both unhealthy tailpipe emissions and the emissions of gases that cause global warming.

"Whether you are looking to buy a compact car, large car, pickup, minivan, or SUV, the Green Book takes the guesswork out of identifying which models are friendlier to the environment," said James Kliesch, a Research Associate at the council.

The council each year names the "greenest" and "meanest" vehicles, along with environmental scorings of all model year cars and passenger trucks. This is the tenth year they have published the respected rankings.

Claiming the prize as the greenest model year 2007 vehicle is Honda's natural gas-powered Civic GX.

The Toyota Prius and Honda Civic Hybrid, stalwarts on the annual "Greenest Vehicles" list, claim spots two and three, while the Nissan Altima Hybrid and Toyota Yaris, market newcomers for model year 2007, round out the top five.

Others in the list include conventional and hybrid-electric vehicles from Honda, Hyundai, Kia, and Toyota.

Domestic automakers were shut out of the top-twelve list.

"We've seen a lot of advertising this past year about efficient and eco-friendly vehicles being offered by domestic manufacturers. But when you look at the specs that matter, it's fair to say the imports have Detroit's number," said Kliesch.

He blames the absence of domestic brands from the list on their wavering approach to fuel-efficient technologies.

"Certain companies committed years ago to fuel-efficient technologies and held firm to those commitments. Today, those automakers have a clear competitive advantage in the world of green vehicles," Kliesch said. provides information to examine the eco-performance of any 2007 model.

Mean & Dirty

This year's "Meanest Vehicles for the Environment," a list traditionally dominated by large domestic pickups and SUVs, contains only four models from Detroit.

European imports make up the remainder of the list.

Much of the reason for that shift is the arrival of a number of new diesel models that meet some of the dirtiest tailpipe emissions standards allowable in the United States.

Five diesels populate the year's twelve-worst list, including the year's most environmentally unfriendly model, the diesel-powered Volkswagen Touareg.

Rounding out the "bottom five" are the Mercedes-Benz GL320 CDI, Lamborghini Murcielago, diesel-powered Jeep Grand Cherokee, and Bentley Arnage RL.

Prominent gasoline models on the list include the Dodge Ram 2500 Mega Cab pickup, Ford F-250 pickup, and Lincoln Navigator SUV.

"Given the arrival this year of ultra-low-sulfur diesel fuel, having five diesels show up on the Meanest Vehicles list is a letdown," said Therese Langer, Transportation Program Director at the council.

"Fortunately, these same manufacturers have already announced plans to bring much cleaner diesels to the United States in 2008, using an entirely different emissions control strategy."

While diesels are more efficient than gasoline-powered vehicles with similar performance, they produce higher levels of environmentally damaging nitrogen oxides and particulate matter and consequently require more sophisticated emissions control.

Greener Choices

The Web site also identifies a selection of top widely available models in each vehicle class.

This "Greener Choices" list includes larger vehicles, such as the Ford Escape Hybrid SUV, GMC Sierra Classic C1500 pickup, and Toyota Sienna minivan. Passenger cars such as the Hyundai Sonata and Ford Focus Wagon also top their respective classes.

As the list demonstrates, consumers can make greener choices,whether they need a sedan, minivan, pickup truck, or SUV.

"We must boost fuel economy if we hope to replace oil with biofuels or any other energy source. The good news is that we can boost fuel economy with the technologies on our Greenest Vehicles list, easing our pain at the pump while revitalizing our auto industry and slowing global warming," said Bill Prindle, ACEEE's acting Executive Director.