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

In-house test program report No. 2: vehicle preconditioning LA-4 vs. HFET. Technical support report

Technical Report ·
OSTI ID:5223861

The purpose of this study was to determine whether or not the two Highway fuel economy test (HFET) cycles used for measuring fuel economy would be suitable for a preconditioning driving cycle in place of one urban dynamometer driving schedule (LA-4). The main concern with using the HFET was the possibility that the purge characteristics of the evaporative emission control system would allow for purging during preconditioning and not during the exhaust emission cycle which is essentially the same as an LA-4. If this were to occur then sufficient canister capacity would enable a vehicle to pass the evaporative emissions test, and the exhaust test would be easier to pass due to the fact that hydrocarbons from the canister would not be purging into the engine.

Research Organization:
Environmental Protection Agency, Ann Arbor, MI (USA)
OSTI ID:
5223861
Report Number(s):
PB-270365; EVAP-75-5
Country of Publication:
United States
Language:
English