Heavy-Duty Gasoline Engine Emission Sensitivity to Variations in the 1984 Federal Test Cycle

An attempt at quantification of emission sensitivity of heavy-duty gasoline engines to variations in the 1984 Federal Certification transient test cycle was made. A brief overview of the Federal Test Procedure is presented, followed by emission test results from several dynamometer controller miscalibration modes. In general, the results indicated that certain modes of controller calibration can produce significant emission variations well within the limits of the 1984 FTP validation criteria. The data indicated that some validation criteria require tightening or respecification to assure repeatable test results.