CFR›Title 40›Chapter I›Part 1036›Subpart C›40 CFR 1036.231 Citation40 CFR 1036.231CorpusDaily eCFRDisplayed edition2026-04-15Last updated2026-04-15 § 1036.231 xxxLink to an amendment published at 91 FR 7778, Feb. 18, 2026. Previous 1036.230 § 1036.230 Selecting engine families. Next 1036.235 § 1036.235 Testing requirements for certification.