A Brief Treatise on the Problems Associated with Using one Vehicle to Determine the Dynamometer Power Absorption for a Second Similiar Vehicle

摘要

The current EPA regulations for exhaust emission certification and fuel economy measurements allow a manufacturer the option of road testing a vehicle to determine a dynamometer adjustment which will subsequently be used for all vehicles of a similar class. In the process of using the road test results from one vehicle to determine the dynamometer adjustment for a second vehicle there is the potential for error. This report briefly discusses the magnitude of these possible errors. Two specific cases are considered. In the first case the error is assumed that good engineering practices are used. In the second case it is assumed that the potential for error is used in a systematic manner to result in a reduced loading for the second vehicle.