(a) Vehicles are subject to cold temperature testing requirements as described in subpart S of this part and 40 CFR part 600.

(b) Migration to 40 CFR parts 1065 and 1066. This subpart transitions to rely on the test procedure specifications in 40 CFR parts 1065 and 1066 as follows:

(1) Through model year 2021, manufacturers may use the test procedures specified in paragraph (c) or (d) of this section or, using good engineering judgement, elements of both. For any EPA testing before model year 2022, EPA will use the manufacturer's selected procedures for applying acceptable speed-tolerance criteria. For any other parameters, EPA may conduct testing using either of the specified procedures. As allowed under this part, manufacturers may use carryover data from previous model years to demonstrate compliance with emission standards, without regard to the provisions of this section.

(2) For vehicles certified before model year 2022 to any of the Tier 3 emission standards specified in subpart S of this part, manufacturers must determine overall driver accuracy based on driven cycle energy as described in 40 CFR 1066.425(j).

(c) Interim procedures. Through model year 2021, manufacturers may certify vehicles based on data collected according to previously published cold temperature and intermediate temperature testing procedures.

(d) Long-term procedures. Starting in model year 2022, perform testing to measure CO and NMHC emissions and determine fuel economy as described in 40 CFR part 1066; see especially 40 CFR 1066.710. We may approve the use of previously published cold temperature and intermediate temperature testing procedures for later model years as an alternative procedure under 40 CFR 1066.10(c). Perform intermediate temperature testing as follows:

(1) For testing during ambient temperatures of less than 50 °F (10 °C), perform testing as described in 40 CFR part 1066, subpart H.

(2) For testing at temperatures of 50 °F (10 °C) or higher, perform FTP testing as described in 40 CFR part 1066.

(e) Section 86.213 describes special provisions related to test fuel specifications.

(a) Gasoline. Use a gasoline test fuel with ethanol (low-level blend only) or without ethanol as follows:

(1) You must certify using service accumulation fuel and E10 test fuel as specified in § 86.113 for any vehicles required to use a low-level ethanol-gasoline blend test fuel for measuring exhaust emissions. You may use this test fuel any time earlier than we specify.

(2) You may use the test fuel specified in this paragraph (a)(2) for vehicles that are not yet subject to exhaust testing with an ethanol-blend test fuel under § 86.113. Manufacturers may certify based on this fuel using carryover data until testing with the ethanol-blend test fuel is required. The following specifications apply for gasoline test fuel without ethanol:

(3) Manufacturers may use the E0 gasoline test fuel specified in § 86.113 for certification instead of the fuel specified in paragraph (a)(2) of this section, as long as the change in test fuel does not cause cold temperature NMHC, CO, or CO2 emissions to decrease; manufacturers must keep records documenting these emission effects and make them available to EPA upon request.

(4) We may approve alternate fuel specifications that are substantially equivalent to those in paragraph (a)(2) of this section for a manufacturer's testing.

(b) [Reserved]