Kermit the Frog may have been right about the difficulties of being green, but a growing number of automakers are trying.
An annual online rating of what's "green" and what isn't, published today, has four new models on its list of the dozen most environmentally friendly vehicles for 2007.
Equally notable, though, is the large number of vehicles that nearly made the list in the Green Book, an environmental guide to cars and trucks by the American Council for an Energy-Efficient Economy in Washington.
"There are a lot of eco-friendly vehicles that just missed the cut" for the top 12 ranking, Green Book author James Kliesch said.
"It used to be the case that the greenest vehicles were a select number of models that stood far above the pack," he said. "Today, the eco-friendly field has become much more crowded, and that's good news for consumers."
Honda Motor Co.'s natural-gas-powered Civic GX was the nation's greenest vehicle for the third time in four years -- after being knocked into second place last year by the company's since-discontinued two-seat Insight gasoline-electric hybrid.
Toyota Motor Corp.'s popular Prius, another gasoline-electric hybrid, was second, followed closely by Honda's Civic hybrid.
Two newcomers -- Nissan Motor Co.'s Altima hybrid, which went on sale this month, and Toyota's Yaris subcompact -- rounded out the top five. The other newcomers are Toyota's Camry hybrid, in seventh place, and Honda's Fit subcompact, in eighth.
A third new subcompact in the market, Nissan's Versa, was one of a growing number of vehicles that scored well but not high enough to make the top rankings.
Kliesch said one version of the Versa fell just behind the 12th-place finisher, Honda's gasoline-powered Civic sedan with a 1.8-liter four-cylinder engine and automatic transmission.
But the Versa has a bigger standard engine than most vehicles in the top rankings and is just a bit heavier and slightly less fuel-efficient than its competition. The combined city and highway mileage ratings for the Yaris and Fit range from 33 to 37 miles per gallon; the best the Versa could do was 32 mpg.
The dozen greenest cars this year are Asian models, blanking out American automakers for only the second time in the 10 years the Green Book has been published. Japanese automakers captured nine of the top 12 positions, and South Korean car companies took the three others.
