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Emission Test Cycles

EPA Highway Fuel Economy Test Cycle (HWFET)

Time-speed data points | 10 Hz file

The Highway Fuel Economy Test (HWFET or HFET) cycle is a chassis dynamometer driving schedule developed by the US EPA for the determination of fuel economy of light-duty vehicles [40 CFR 600, subpart B]. The HWFET is used to determine the highway fuel economy rating, while the city rating is based on the FTP-75 test. Since 2008, supplemental FTP tests (US06 and SC03) are additionally used for the determination of the EPA on-road fuel economy values.

Figure 1. EPA Highway Fuel Economy Test Cycle

The test is run twice, with a break of maximum of 17 s between the runs. The first run is a vehicle preconditioning sequence, the second run is the actual test with emission measurement.

The following are some characteristic parameters of the cycle:

  • Duration: 765 seconds
  • Total distance: 10.26 miles (16.45 km)
  • Average Speed: 48.3 mi/h (77.7 km/h)