§ 86.016-1 General applicability.

(a) Applicability. The provisions of this subpart apply for certain types of new heavy-duty engines and vehicles as described in this section. As described in paragraph (j) of this section, most of this subpart no longer applies starting with model year 2027. Note that this subpart does not apply for light-duty vehicles, light-duty trucks, medium-duty passenger vehicles, or vehicles at or below 14,000 pounds GVWR that have no propulsion engine, such as electric vehicles; see subpart S of this part for requirements that apply for those vehicles. In some cases, manufacturers of heavy-duty engines and vehicles can choose to meet the requirements of this subpart or the requirements of subpart S of this part; those provisions are therefore considered optional, but only to the extent that manufacturers comply with the other set of requirements. In cases where a provision applies only for a certain vehicle group based on its model year, vehicle class, motor fuel, engine type, or other distinguishing characteristics, the limited applicability is cited in the appropriate section. The provisions of this subpart apply for certain heavy-duty engines and vehicles as follows:

(1) The provisions of this subpart related to exhaust emission standards apply for diesel-cycle and Otto-cycle heavy-duty engines installed in vehicles above 14,000 pounds GVWR; however, these vehicles may instead be certified under subpart S of this part in certain circumstances as specified in § 86.1801.

(2) The provisions of this subpart related to exhaust emission standards apply for engines that will be installed in incomplete heavy-duty vehicles at or below 14,000 pounds GVWR; however, these vehicles may instead be certified under subpart S of this part as specified in § 86.1801.

(3) Diesel-cycle and Otto-cycle complete heavy-duty vehicles at or below 14,000 pounds GVWR and the corresponding engines are not subject to the provisions of this subpart related to exhaust emission standards, except that these provisions are optional for diesel-cycle engines installed in such vehicles until those vehicles become subject to the Tier 3 standards under § 86.1816–18.