What RPM is primarily used during the second stage of the tailpipe test?

During the second stage of the tailpipe test, which is crucial in assessing a vehicle's emissions under a simulated driving condition, the RPM primarily utilized is 2500 RPM. This testing stage simulates a standard driving environment where the engine operates efficiently at higher RPMs, allowing assessors to accurately measure the emissions output.

At 2500 RPM, the engine is revved to a level that reflects typical acceleration and cruising conditions, enabling the capture of data on how various components of the vehicle's emissions system perform at this speed. This RPM range is critical for identifying potential issues like incomplete combustion or malfunctioning emissions controls, as many vehicles produce their peak emissions at this RPM during real-world driving scenarios.

Using this RPM helps ensure that the results obtained during the test are representative of the vehicle's actual performance, making it a vital parameter in determining compliance with emissions standards.