(a) The procedures of this part 1066 may be used for testing at any ambient temperature. Section 1066.710 describes the provisions that apply for testing vehicles at a nominal temperature of -7 [deg]C (20 [deg]F); these procedures apply for motor vehicles as described in 40 CFR part 86, subpart S, and 40 CFR part 600. For other vehicles, see the standard-setting part to determine if your vehicle is required to meet emission standards outside the normal (20 to 30) [deg]C ((68 to 86) [deg]F) temperature range.
(b) Do not apply the humidity correction factor in Sec. 1066.615(a) for cold temperature testing. [79 FR 23823, Apr. 28, 2014, as amended at 80 FR 9122, Feb. 19, 2015]