CAFE data collection and verification

The United States has implemented the corporate average fuel economy regulation for light-duty vehicles for more than thirty years, with laudable enforcement. A sound data collection and verification system is crucial for effective enforcement. This working paper summarizes key procedures in fuel economy data collection and verification in the United States.

Key steps in fuel economy data collection and verification under the US CAFE system are:

1. Manufacturers test 90 percent of vehicle sales by configuration and report the data to EPA
2. EPA reviews and judges the acceptability of manufacturer reported data
3. In addition to reviewing manufacturer data, EPA conducts confirmatory test for 10-15 percent of fuel economy data vehicles and determines the fuel economy of test vehicles based on comparison of its own results and the data from manufacturers
4. After manufacturers submit the actual production data of a model year, EPA calculates and verifies the average fuel economy of the manufacturers.