USDOT Answers & FAQs

You can find statistics on fuel economy in National Transportation Statistics, Table 4-23 Average Fuel Efficiency of U.S. Passenger Cars and Light Trucks:   http://www.bts.gov/publications/national_transportation_statistics/html/table_04_23.html

This data comes from the following sources:

Federal Highway Administration, Highway Statistics, Table VM-1 (historical data): http://www.fhwa.dot.gov/policy/ohpi/qftravel.cfm

Most current VM tables in Highway Statistics 2010 http://www.fhwa.dot.gov/policyinformation/statistics/2010

National Highway Traffic Safety Administration, October 2011 Summary of Fuel Economy Performance:  
http://www.nhtsa.gov/staticfiles/rulemaking/pdf/cafe/October_2011_Public.pdf

For more information on Corporate Average Fuel Economy (CAFE) standards, see http://www.nhtsa.gov/fuel-economy?ruleSortBy=part&ruleOrder=asc

The U.S. Department of Energy (DOE) also has a table available based on the Highway Statistics data called "Motor Vehicle Mileage, Fuel Consumption, and Fuel Rates, Selected Years, 1949-2008: http://www.eia.gov/totalenergy/data/annual/pdf/sec2_25.pdf

To look up fuel economy information by make and model, see the following sites.  

Environmental Protection Agency, Green Vehicle Guide:
http://www.epa.gov/greenvehicles/Index.do;jsessionid=8230f7b4d9a0c7e5f7b1

Fueleconomy.gov, Find a Car:
http://www.fueleconomy.gov/feg/findacar.htm