The Energy Department and the Environmental Protection Agency say the labels can be downloaded or viewed on the website www.fueleconomy.gov.
Labels are available for all vehicles sold in the U.S. since 1984. They show mileage and carbon dioxide emissions estimates.
The government said the stickers are valid for used cars because mileage changes little over a vehicle's 15-year life if it's maintained properly.
Used car sellers and dealers can post the stickers on car windows to advertise mileage. Buyers can search the site for the models they want to buy.