(a) Park the motor vehicle on the test site as specified in section 453.2 of this Part. If the motor vehicle is a combination of vehicles, park the combination so that the longitudinal centerlines of the towing vehicle and the towed vehicle or vehicles are in substantial alignment.

(b) Turn off all auxiliary equipment which is installed on the motor vehicle and which is designed to operate under normal conditions only when the vehicle is operating at a speed of five mph (eight kph) or less. Examples of such equipment include cranes, asphalt spreaders, liquid or slurry pumps, auxiliary air compressors, welders and trash compactors.

(c) If the motor vehicle's engine radiator fan drive is equipped with a clutch or similar device that automatically either reduces the rotational speed of the fan or completely disengages the fan from its power source in response to reduced engine cooling loads, park the vehicle before testing, with its engine running at high idle or any other speed the operator may choose, for sufficient time, but not more than 10 minutes, to permit the engine radiator fan to automatically disengage when the vehicle's noise emissions are measured under stationary test.

(d) With the motor vehicle's transmission in neutral and its clutch engaged, rapidly accelerate the vehicle's engine from idle to its maximum governed speed with wide-open throttle. Return the engine's speed to idle.

(e) Observe the maximum reading on the sound level measurement system during the time the procedures specified in subdivision (d) of this section are followed. Record that reading, if the reading has not been influenced by extraneous noise sources such as motor vehicles operating on adjacent roadways.

(f) Repeat the procedures specified in subdivisions (d) and (e) of this section until the first two maximum sound level readings that are within two dB(A) of each other are recorded. Numerically average those two maximum sound level readings. When appropriate, correct the average figure in accordance with Part 454 of this Title.

(g) The average figure, corrected as appropriate, contained in accordance with subdivision (f) of this section, is the sound level generated by the motor vehicle for the purpose of determining whether it conforms to the sound level limit set forth in section 38(3)(b) of the New York State Vehicle and Traffic Law. (Table 1 in section 450.3 lists the range of maximum permissible sound level readings for various test conditions.)