
Emissions
The objective of this test is to provide accurate, comparable gas and particulate emissions data for transit buses produced by different manufacturers while operating the vehicle over a simulated transit duty cycle on a dynamometer [download full test procedure]. The test will be performed on a engine after the bus has accumulated several thousand miles of operation, thus providing a more realistic indication of the level of emissions that can be expected in actual transit service. The results of this test may be used by transit operators for making relative comparisons between buses. The test is performed using a large-roll chassis dynamometer.
Please Note: This is not the same procedure that is used to meet the Environment Protection Agency (EPA) for engine certification.