Gasoline, Diesel, and Alternative Fuel Heavy-Duty Engine Auditing 

Manufacturers of gasoline, diesel, and alternative fuel heavy-duty engines periodically audit their products to assure compliance with Environmental Protection Agency (EPA) emissions regulations. These audits allow the manufacturer to monitor production-line performance and diagnose problems before they become serious.

With more than 15 years of experience with EPA procedures, Southwest Research Institute (SwRI) conducts certification-quality emissions tests. The audit begins with the shipment of a representative sample of end-of-line (EOL) engines to the Institute. Test engines are outfitted with the necessary accessories and installed in a test cell by SwRI technicians. The engines are then broken in according to the manufacturer specifications.
 

All SwRI transient emissions test cells meet EPA specifications for heavy-duty gasoline or diesel engine certification.

On-Highway Engines

For on-highway engines, a power validation and torque map are  performed in preparation for the transient emission test. The cold-start portion of the test begins after a natural overnight soak or an optional forced cool-down.

Nonroad Engines

For nonroad diesel engines, the eight-mode, Part 89 steady-state test procedure is used.

Federal smoke tests are typically run for both on-highway and nonroad engines. Following testing, engines are crated and returned to the manufacturer.

In addition to EOL testing, SwRI conducts selective enforcement audits (SEA) and production compliance audits (PCA) for manufacturers. SEA and PCA testing is monitored by the EPA, and results are reported to both the manufacturer and EPA.

SwRI facilities include two test cells equipped to run spark-ignited engines, six test cells for diesel engines, and two flexible cells that accommodate diesel, gasoline, or alternative fuel engines.
 

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