(a) At the start of each model year, the manufacturer will begin to select engines from each Category 1 and Category 2 engine family for production line testing. Each engine will be selected from the end of the production line. Testing shall be performed throughout the entire model year to the extent possible. Engines selected shall cover the broadest range of production possible.

(1)

(i) The required sample size for Category 1 engine manufacturers is one percent of projected annual U.S.-directed production for all Category 1 engine families, provided that no engine tested fails to meet applicable emission standards. Test engines shall include a proportional sample from each engine family. The required sample size is zero if a manufacturer's projected annual production for all Category 1 engine families is less than 100.

(ii) The required sample size for a Category 2 engine family is one percent of projected annual U.S.-directed production for that engine family, with a minimum sample size of one test per model year provided that no engine tested fails to meet applicable emission standards.

(2) Manufacturers may elect to test additional engines. All additional engines must be tested in accordance with the applicable test procedures of this part.

(3) The Administrator may reject any engines selected by the manufacturer if he/she determines that such engines are not representative of actual production.

(b) The manufacturer must assemble the test engines using the same mass production process that will be used for engines to be introduced into commerce.

(c) No quality control, testing, or assembly procedures will be used on any test engine or any portion thereof, including parts and subassemblies, that have not been or will not be used during the production and assembly of all other engines of that family, except with the approval of the Administrator.

[64 FR 73331, Dec. 29, 1999, as amended at 68 FR 9787, Feb. 28, 2003]