This SAE Recommended Practice applies to a productiondynamometer test procedure which can be used to measure the smokeand gaseous emission characteristics of vehicular diesel engines.This procedure describes the smoke emission test method, smoke testcycle, gaseous emission test method, steady-state gaseous emissiontest cycle, equipment, instrumentation, calibration, data analysis,and correlation of results for comparison of production engineemission performance to the requirements of current or past Federalregulations.

Variations in engines, instrumentation, and test equipment mayrequire modifications to these procedures or data reductionmethods. The acceptability of this procedure is dependent upondocumented statistical data appropriate to correlate all tests,data reduction techniques, and special instrumentation to therequired Federal tests.

When using the audit test procedure to assess the emissionsperformance of production engines, considerations should be givento expected emissions deterioration factors and quality controllimits should be adjusted accordingly.

This document is intended as a guide for the measurement andassessment of transient smoke and steady-state gaseous emissionsfrom heavy duty vehicular diesel engines only using a shortenedengine dynamometer cycle which may be applicable to production lineor production quality audit conditions. Key elements of theprocedure closely resemble key elements of the Federal TestProcedures used for regulatory approval by the United StatesGovernment.