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U.S. Department of Energy
Office of Scientific and Technical Information

Comparison of fuel economy values from the preconditioning and measuring cycles of the highway fuel economy test procedures. Technical report

Technical Report ·
OSTI ID:5395053

The Highway Fuel Economy Dynamometer Procedure consists of driving the test vehicle over two highway driving cycles with fifteen seconds of idle between them. The first cycle is for preconditioning and the second is for fuel economy determination. This procedure is designed to follow the Federal Emission Test Procedure. If, however, it cannot be scheduled within three hours of the FTP, the vehicle will be re-driven over one cycle of the EPA Urban Dynamometer Driving Schedule, known as the LA-4, before running the two highway driving cycles. Since the vehicles are driven either over a FTP or a LA-4 prior to the highway fuel economy test, the vehicles may already be in a stabilized condition during the first cycle. Therefore, a study was conducted to determine if it is necessary to run the second highway cycle. This report presents summary statistics of the absolute and relative % differences between the fuel economy determinations of the two cycles and compares these differences to the time elapsed between the end of the FTP (or LA-4) and the start of the highway test.

Research Organization:
Environmental Protection Agency, Ann Arbor, MI (USA)
OSTI ID:
5395053
Report Number(s):
PB-298170
Country of Publication:
United States
Language:
English