CFR /  Title 40  /  Part 90  /  Sec. 90.302 Definitions.

The definitions in Sec. 90.3 apply to this subpart. The following definitions also apply to this subpart.

Intermediate speed means the engine speed which is 85 percent of the rated speed.

Natural gas means a fuel whose primary constituent is methane.

Rated speed means the speed at which the manufacturer specifies the maximum rated power of an engine. [64 FR 15243, Mar. 30, 1999]