§ 86.1827-01 Test group determination.

This section applies to the grouping of vehicles into test groups within a durability group. The vehicles covered by an application within a durability group shall be divided into test groups based on the following criteria. The manufacturer shall use good engineering judgment in grouping vehicles into test groups.

(a) To be included in the same test group, vehicles must be identical in all following respects:

(1) Durability group;

(2) Engine displacement (within a total band width of 15 percent of the largest displacement or 50 CID, whichever is larger);

(3) Number of cylinders or combustion chambers;

(4) Arrangement of cylinders or combustion chambers (e.g. in-line, v-shaped);

(5) Subject to the same emission standards (except for CO₂), or FEL in the case of cold temperature NMHC or NMOG+NO_X standards, except that a manufacturer may request to group vehicles into the same test group as vehicles subject to more stringent standards, so long as all the vehicles within the test group are certified to the most stringent standards applicable to any vehicle within that test group. For example, manufacturers may include medium-duty vehicles at or below 22,000 pounds GCWR in the same test group with medium-duty vehicles above 22,000 pounds GCWR, but all vehicles included in the test group are then subject to the off-cycle emission standards and testing requirements described in § 86.1811-27(e). Light-duty trucks and light-duty vehicles may be included in the same test group if all vehicles in the test group are subject to the same criteria exhaust emission standards.