The U.S. Environmental Protection Agency (EPA) and the Department of Energy (DOE) released the 2011 Fuel Economy Guide, providing consumers with information about estimated mileage and fuel costs for model year 2011 vehicles.

"Increasing fuel efficiency is important for our environment, our economy and our health - and it helps families save money at the pump," EPA Administrator Lisa P. Jackson said. "This guide will help consumers make the right choice for the environment and for their wallets when buying a car."

"This year's Fuel Economy Guide will allow consumers to choose fuel efficient vehicles that will save them money at the pump, while helping to reduce our dependence on foreign oil and limiting carbon pollution," said Energy Secretary Steven Chu. "Fuel efficient vehicles help reduce driving costs for American families while continuing to deliver the highest standards of vehicle performance."

Fuel efficient models come in all types, classes, and sizes. Overall, the best fuel economy performers are hybrids, but the 2011 fuel economy leaders also include fuel efficient clean diesels as well as gasoline models.

Each vehicle listing in the guide provides an estimated annual fuel cost. The estimate is calculated based on the vehicle's miles per gallon (mpg) rating and national estimates for annual mileage and fuel prices. The online version of the guide allows consumers to input their local gasoline prices and typical driving habits to receive a personalized fuel cost estimate.

For the first time, the guide includes medium-duty passenger vehicles, which are generally large sport utility vehicles (SUVs) and passenger vans. These vehicles were not previously subject to fuel economy measurement and labeling requirements.

EPA and DOE will provide additional fuel economy information online as more 2011 vehicles, including electric and plug-in hybrid cars, become available.

The Top 10 Most Fuel-Efficient Cars for 2011 Model Years:

1. 2011 Toyota Prius: 51/48 mpg city/highway

2. 2011 Ford Fusion hybrid, Milan hybrid, Lincoln MKZ hybrid: 41/36 mpg city/highway

3. 2011 Honda Civic hybrid: 40/43 mpg city/highway

3. 2011 Honda Insight hybrid: 40/43 mpg city/highway

4. 2011 Honda CR-Z (auto): 35/39 mpg city/highway

5. 2011 Lexus HS 250h: 35/34 mpg city/highway

6. 2011 Ford Escape hybrid, Mazda Tribute hybrid, Mercury Mariner hybrid: 34/31 mpg city/highway

7. 2011 Smart ForTwo: 33/41 mpg city/highway

8. 2011 Nissan Altima hybrid: 33/33 mpg city/highway

9. 2011 Lexus RX 450h: 32/28 mpg city/highway

10. 2011 Honda CR-Z (manual): 31/37 mpg city/highway