A Chassis Test Procedure to Mimic the Heavy-Duty Engine Transient Emissions Certification Test

摘要

In-use emissions from vehicles using heavy-duty diesel engines can be significantly higher than the levels ob- tained during engine certification. These higher levels may be caused by a combination of degradation of en- gine components, poor engine maintenance, degrada- tion or failure of emissions after-treatment devices, and engine and emissions system tampering.