Environmental car data released by WhatGreenCar today shows that the latest 2010 range of new cars available in the U.S. is 6.6% greener than the 2009 Model Year (MY) range.

The WhatGreenCar Ratings also demonstrate that the shift to green is gaining pace – to date, this year's 6.6% reduction is more than three times last year's improvement of 2.1%.

Comparing MY2009 cars with the latest MY2010 line-up, 10 volume manufacturers are now offering a new model range above the average improvement of 6.6%. The 'Top 10' manufacturers achieving this are: Chevrolet (20.3% improvement), GMC (15.3%), Mercedes-Benz (13.6%), Lexus (13.2%), Mercury (11.6%), Kia (11.0%), Ford (10.4%), Acura (8.0%), Volkswagen (8.0%), and Suzuki (7.7%).

According to Dr Ben Lane, Managing Editor of WhatGreenCar: "U.S. car makers are making huge strides to produce smaller, more fuel-efficient cars as well as pushing fast into the electric and hybrid markets. Cars such as the Chevrolet Volt [pictured] and the Lexus HS 250h hybrid are proof that the U.S. auto industry is genuinely trying to clean up its act as well as producing cars that consumers want to buy".

For the first time, the WhatGreenCar Vehicle Ratings allow the emerging trend for models with lower environmental impact to be tracked, and show which manufacturers are doing most to green their range. The following table shows which of the major automakers currently have the greenest line-up of 2009/10 models – the Top 10 includes many of the key manufacturers of small and/or hybrid cars.

The WhatGreenCar Ratings also show which companies have the most polluting cars in their showrooms. Although this is subject to change as new 2010 models are released, the table below shows the current (volume) producers of the least green cars in the U.S.

With interest in fuel economy and the environment on the rise, WhatGreenCar provides all the information consumers need to buy a green car – one that saves money as well as the planet.

The site can search for ratings for over 6000 U.S. models (2008 through 2010), including gasoline, hybrid, ethanol, diesel and natural gas (CNG) vehicles. Environmental ratings are given for both Federal and California sales areas. During the fall, Models Years 2001-07, and ratings for the latest electric and fuel cell vehicles will also be available.

To find Vehicle Ratings for specific models in the U.S., click here.