Engine Testing Procedures

EPA has adopted emission standards for almost every kind of engine, including everything from lawn mowers to cruise ships. To show compliance with these emission standards, engine manufacturers must follow test procedures specified in the Code of Federal Regulations. This page provides links to the appropriate regulatory citations and includes published information related to the test procedures. These links include a general set of instructions and requirements for manufacturers to measure emissions for certifying their engines to EPA emission standards. Manufacturers should also read the regulations for category-specific provisions that apply.

The test procedures referenced on this page are related to engine-based exhaust emission standards. All types of engines are subject to the procedures in 40 CFR part 1065, excluding aircraft engines and those that require vehicle testing