The Tesla S and the Toyota RAV4 EV scored top points on the Automobile Assn. of America's Green Car Guide, followed by the Audi A7 TDI, the Lexus GS and the Nissan Leaf.
The listings are part of AAA's annual alternative fuel car report, a 140-page tome that reviews 80 hybrids, electric cars, CNG-powered cars, clean diesels and partial zero emissions vehicles. The study was conducted by the automobile club's Automotive Research Center.
The center's manager and chief engineer, Steve Mazor, called the Tesla S "an incredible car," and "the fastest green car we've ever tested." He acknowledged concern about the Tesla's 265-mile range and slow charging time, but said: "The Model S was our top-scoring vehicle this year by a wide margin."
It's not tops for value, though. That title was won by the Chevrolet Spark, which was named best green car value vehicle for 2014.
Chasing it were the Hyundai Elantra GLS, the Nissan Versa SV, the Scion iQ and the Nissan Versa Note SV.
Meanwhile, another group has also issued the results of a green car-by-car comparison, and put Hyundai-Kia on top.
The Korean automaker is the "greenest," according to the Union of Concerned Scientists' latest Automaker Rankings report.
In winning, Hyundai-Kia stole first place from Honda, which has won the Union of Concerned Scientists' top award every year since the group began giving the awards, the first going to cars from model year 1998.
Honda came in second this time, followed by Toyota, Nissan and Volkswagen tied for third, and then with Ford, GM and Chrysler "bringing up the rear," the report said.
Overall, the scientists said, the country's eight top-selling automobile companies all improved their environmental performance -- the first time that's happened in the history of the study.
"For too many years, clean car standards were stagnant and automakers were more likely to promote extra cup holders instead of fuel economy," said Dave Cooke, author of the study. "Now, consumers are demanding cars that go further on a gallon of gas."