Chevrolet made the biggest year-to-year gain in "green" attributes for its 2010 model line, followed by GMC, Mercedes and Lexus, according to WhatGreenCar.
In other rankings, WhatGreenCar looked at which companies offer the "greenest" cars. Coming in at the top was Mini, followed by Pontiac, Volkswagen, Honda and Suzuki.
By contrast, the five worst polluting car brands are: Lamborghini, Rolls-Royce, Land Rover, Hummer and Isuzu.
Individual ratings for cars can be found here.
