Transient versus Steady State Test Procedure Evaluation of 4-Cycle Utility Engines

In 1995, the United States Environmental Protection Agency published the first phase of regulation for utility engines defined as certain new non-road spark ignited engines that have a gross power output at and below 19 kW. The first phase was adapted from the existing California Tier I Regulation with the understanding that the second phase of EPA regulation would be a thorough review of the first phase. This paper reports the results of the test procedure evaluation pertaining to this second phase of regulation. The information includes field evaluation of the equipment for in-use operating characteristics, application of known steady state emissions tests procedures and new transient procedures, and a comparison of the results.