§ 1066.710 Cold temperature testing procedures for measuring CO and NMHC emissions and determining fuel economy.
This section describes procedures for measuring carbon monoxide (CO) and nonmethane hydrocarbon (NMHC) emissions and determining fuel economy on a cold day using the FTP test cycle (see § 1066.801).
(a) Follow the exhaust emission measurement procedures specified in §§ 1066.410 through 1066.425 and § 1066.815(d), subject to the following exceptions and additional provisions:
(1) Measure and control ambient conditions as specified in paragraph (b) of this section.
(2) Use the vehicle's heater and defroster as specified in paragraph (c) of this section.
(3) Precondition and stabilize the vehicle as specified in paragraphs (d) and (e) of this section. Ensure that there is no precipitation or dew on the vehicle before the emission test.
(4) For dynamometers that have independently heated bearings, start the emission test within 20 minutes after warming up the dynamometer; for other types of dynamometers, start the emission test within 10 minutes after warming up the dynamometer.
(5) Adjust the dynamometer to simulate vehicle operation on the road at −7 °C as described in § 1066.305(b).
(6) Analyze samples for NMHC, CO, and CO2. You do not need to analyze samples for other pollutants.
(b) Maintain ambient conditions as follows instead of following the specifications in subpart E of this part:
(1) Ambient temperature for emission tests. Measure and record ambient temperature in the test cell at least once every 60 seconds during the sampling period. The temperature must be (−7.0 ±1.7) °C at the start of the test and average temperature must be (−7.0 ±2.8) °C during the test. Instantaneous temperature values may be above −4.0 °C or below −9.0 °C, but not for more than 3 minutes at a time during the test. At no time may the ambient temperatures be below −12.0 °C or above −1.0 °C.