Degradation Effects on Motor Vehicle Exhaust Emission.

摘要

A study was conducted to determine the effects of vehicle maintenance practices on exhaust emissions. Four groups of 144 1968to 1974light duty vehicles,representative of California's population in 1975were evaluated. The groups represented (1) a control group, (2) a 50% pass-fail idle test inspection, (3) manufacturers specification and (4) mandatory maintenance and parameter inspection. All vehicles entering the test program received a baseline 1973Federal CVS emission test,followed by a hot-idle test (low and 2,500rpm). Adjustment or repair of vehicles was accomplished by Olson Laboratories for Group II and Group III vehicles. Class A garages performed maintenance on Group IV vehicles. Following the necessary maintenance,the Federal and idle tests were repeated for Group II,Group III,and Group IV vehicles. All vehicles in these groups were retested at 1- 2- 6- 9-and 12-month intervals. This report documents the results of the test program.