U.S. Vehicle Fuel Economy and Certification Records Since 1974

Fuel economy estimates and test data for light-duty vehicles are submitted annually by manufacturers to the U.S. EPA for certification under the Energy Policy and Conservation Act. The EPA validates submissions, performing confirmatory tests on approximately 15% of vehicles. Digital records are available from 1978, with more complete certification data starting in 2008.

Use Cases

• Analyze trends in manufacturer-submitted fuel economy estimates over time to assess compliance with Corporate Average Fuel Economy (CAFE) standards.
• Validate the accuracy of manufacturer test data by comparing it with EPA confirmatory test results for a subset of vehicles.
• Study the evolution of vehicle testing approaches and certification data from paper-based records pre-2008 to digital submissions post-2008.
• Investigate the impact of the 2006 fuel economy calculation formula change by comparing pre- and post-2006 submission data using established conversion mechanisms.

Strengths

• Data collection is mandated by federal law (EPCA and EISA), ensuring systematic annual submissions from manufacturers.
• The EPA performs targeted confirmatory tests on approximately 15% of submitted vehicles to validate manufacturer data.
• Coverage spans from 1974, providing a long-term historical view of U.S. vehicle fuel economy and certification.

Limitations

• Early records (1974-1977) are primarily paper documents that did not undergo the same validation process as later digital data.
• Some data elements, such as estimated sales figures, are marked as Confidential Business Information (CBI) and are not publicly available.
• Fuel economy data prior to 2006 uses a different calculation formula, requiring conversion for direct comparison with modern results.

Provenance

Source

U.S. Environmental Protection Agency (EPA), Office of Transportation and Air Quality (OTAQ).

Collection Method

Mandatory annual submissions from light-duty vehicle manufacturers in XML or document format, stored in EPA's Verify system.

Time Range

1974 to present, with publicly available digital data from 1978 and more complete certification data from 2008.

Freshness

Annual submissions, with the dataset last updated in July 2021.

Geography

United States.