(a) Use the equipment and procedures specified in this subpart and 40 CFR 86.1305 to determine whether engines meet the emission standards in §1036.108.

(b) You may use special or alternate procedures to the extent we allow them under 40 CFR 1065.10.

(c) This subpart is addressed to you as a manufacturer, but it applies equally to anyone who does testing for you, and to us when we perform testing to determine if your engines meet emission standards.

(d) For engines that use aftertreatment technology with infrequent regeneration events, apply infrequent regeneration adjustment factors as described in §1036.530.

(e) Test hybrid engines as described in §1036.525 and 40 CFR part 1065.

(f) Determine engine fuel maps as described in §1036.510(b).

(g) The following additional provisions apply for testing to demonstrate compliance with the emission standards in §1036.108 for model year 2021 and later engines:

(1) If your engine is intended for installation in a vehicle equipped with stop-start technology, you may use good engineering judgment to turn the engine off during the idle portions of the duty cycle to represent in-use operation, consistent with good engineering judgment.

(2) Use one of the following methods to measure CO2 emissions:

(i) Use the ramped-modal cycle specified in §1036.505 using either continuous or batch sampling.

(ii) Measure CO2 emissions over the ramped-modal cycle specified in 40 CFR 86.1362 using continuous sampling. Integrate the test results by mode to establish separate emission rates for each mode (including the transition following each mode, as applicable). Apply the weighting factors specified in 40 CFR 86.1362 to calculate a composite emission result.

(3) Measure or calculate emissions of criteria pollutants corresponding to your measurements to demonstrate compliance with CO2 standards. These test results are not subject to the duty-cycle standards of 40 CFR part 86, subart A.