About the Automotive Trends Data
Key Features of the Trends Database
- The Trends database has been maintained by the EPA since 1975 and is updated annually to include the most up to date data available for all model years.
- All data are based on production volumes delivered for sale in the U.S. by model year and may vary from publicized data based on calendar year sales.
- Data for model years 1975 through 2024 are final and based on official data submitted to the EPA and the National Highway Traffic Safety Administration. Data for model year 2025 are preliminary and based on data provided to EPA by automakers prior to the model year, including projected production volumes.
- The data shown throughout this report are estimated real-world data. Most of the data are reported as fleetwide averages, reflecting harmonic production-weighted averages of individual fuel economy values.
- Major methodological changes are generally propagated backwards through the historical database in order to maintain the integrity of long-term trends.
The Trends database includes all new light-duty vehicles in the United States. Under the NHTSA regulations, new vehicles are separated into two distinct regulatory classes, passenger cars and light trucks, and each vehicle class has separate fuel economy standards. Pickup trucks, vans, and minivans are all classified as light trucks under NHTSA’s regulatory definitions, while sedans, coupes, and wagons are generally classified as cars. Sport utility vehicles can fall into either category, depending on the relevant attributes of the specific vehicle. For more details, see Section 3 of the Full Report.
Regulatory Classes and Vehicle Types Used in This Report
Manufacturers included in this database use the model year 2024 manufacturer definitions determined by the NHTSA for implementation of the Corporate Average Fuel Economy program. When a manufacturer acquires another manufacturer or make, the EPA applies the new manufacturer relationship to all prior model years throughout this report.
Fuel Economy Metrics
The EPA and the NHTSA measure fuel economy for CAFE compliance purposes using the EPA’s city and highway test procedures (the “2-cycle” tests). In addition, the CAFE fleetwide averages are calculated by weighting the city and highway test results by 55% and 45%, respectively. These procedures are required by law for CAFE; however, they no longer accurately reflect real-world driving. Compliance data may also encompass optional performance credits and adjustments that manufacturers can use towards meeting their regulatory requirements.
The data shown throughout this report are estimated real-world data, which supplement the CAFE compliance data using additional laboratory tests to capture a wider range of operating conditions (including hot and cold weather, higher speeds, and faster accelerations) encountered by an average driver. This expanded set of tests is referred to as “5-cycle” testing. The real-world city and highway results are weighted 43% city and 57% highway, consistent with more up to date fleetwide driver activity data. The city and highway values are the same values found on new vehicle fuel economy labels; however, the label combined value is still weighted 55% city and 45% highway, like the CAFE compliance data. Unlike compliance data, which by statute remains unchanged, the method for calculating real-world data has evolved over time, along with technology and driving habits.
| Fuel Economy Data Category | Purpose | Current City/Highway Weighting | Current Test Procedure Basis |
|---|---|---|---|
| Compliance | Basis for manufacturer compliance with standards | 55% / 45% | 2-cycle |
| Estimated Real-world | Best estimate of real-world performance | 43% / 57% | 5-cycle |
All data in this report for model years 1975 through 2024 are final and based on official data submitted to the EPA and the NHTSA as part of the regulatory process. In some cases, this report will show data for model year 2025, which are preliminary and are based on data, including projected production volumes, provided to the EPA by automakers prior to releasing vehicles for sale to the public. All data in this report are based on production volumes delivered for sale in the U.S. by model year. The model year production volumes may vary from other publicized data based on calendar year sales. The report does not examine future model years, and past performance does not necessarily predict future industry trends.
While compliance data is not currently included in this report, it has been included in past reports and should not be compared to real-world data. For additional Trends database details and methodological explanation of fuel economy and calculations throughout the historical database, see the Appendices to the Full Report.