SAE J 2458

This SAE Recommended Practice has been adopted by SAE to specify: a. A basis for net engine retarder power rating; b. Reference inlet air test conditions; c. A method for correcting observed engine retarder power to reference conditions; d. A method for determining net engine retarder power with a dynamometer.

This test code document is applicable to engine exhaust retarders on four-stroke compression ignition (CI), with and without charge air cooling. This document does not apply to aircraft, marine, spark ignition (SI), two-stroke compression ignition (CI) or mechanical super-charged ignition engines, compression release retarders, or combination exhaust and compression release retarders.