§ 86.1908 How must I select and screen my in-use engines?

(a) Once we direct you to do testing under this subpart, you must make arrangements to select test vehicles and engines that meet the following criteria:

(1) The engines must be representative of the engine family.

(2) The usage of the vehicles must be representative of typical usage for the vehicles' particular application.

(3) The vehicles come from at least two independent sources.

(4) The key vehicle/engine systems (e.g., power train, drive train, emission control) have been properly maintained and used.