How We Rate Automobiles

Environmental Impact

Our Environmental Impact Rating for Automobiles is based on a product's fuel consumption, CO2 emissions, manufacturing location and manufacturer's commitment(s) to environmental stewardship (visit the How We Rate page for details). The higher the rating, the lesser the environmental impact of the product, relative to other products within the category. CO2 emissions are calculated using a vehicle's annual fuel consumption, assuming that the average vehicle travels 12,000 miles per year, with a multiplier of 22.2 for diesel-powered vehicles and 19.4 for gasoline-powered vehicles (22.2 = pounds of CO2 emitted per gallon of diesel used; 19.4 = pounds of CO2 emitted per gallon of gasoline used, source: U.S. EPA).

The higher the Environmental Impact Rating, the lesser the environmental impact of the automobile relative to others within the category.

Vehicle MPG data is privided by the U.S. EPA.

Consumption

Our Consumption Rating for Automobiles is based on a product's fuel consumption per mile driven. The Consumption Rating is a comparison of each automobile’s efficiency, expressed as a percentage of the most efficient vehicle within the category.

The higher the Consumption Rating, the more fuel-efficient the vehicle.

Vehicle MPG data is provided by the U.S. EPA.

Lifecycle Cost

Our Lifecycle Cost Rating for Automobiles is determined by a product’s cost of ownership relative to that of other comparable products. The rating calculates the cost to drive a vehicle based on the national average prices for diesel ($2.23), gasoline ($2.05), and ethanol/E85 ($1.87) as of May 4, 2009.

The higher the Lifecycle Cost Rating, the more cost-effective the product.