(a) The provisions of this subpart regarding exemptions are applicable to new and in-use motor vehicles and motor vehicle engines, except as follows:
(1) Beginning January 1, 2014, the exemption provisions of 40 CFR part 1068, subpart C, apply for heavy-duty motor vehicles and engines, except that the competition exemption of 40 CFR 1068.235 and the hardship exemption provisions of 40 CFR 1068.245, 1068.250, and 1068.255 do not apply for motor vehicle engines.
(2) Prior to January 1, 2014, the provisions of §§ 85.1706 through 85.1709 apply for heavy-duty motor vehicle engines.
(b) The provisions of this subpart regarding exclusion are applicable after the effective date of these regulations.
(c) References in this subpart to engine families and emission control systems shall be deemed to apply to durability groups and test groups as applicable for manufacturers certifying new light-duty vehicles, light-duty trucks, and Otto-cycle complete heavy-duty vehicles under the provisions of 40 CFR part 86, subpart S.
(d) In a given model year, manufacturers of motor vehicles and motor vehicle engines may ask us to approve the use of administrative or compliance procedures specified in 40 CFR part 1068 instead of the comparable procedures that apply for vehicles or engines certified under this part or 40 CFR part 86.