40 CFR §1065.122

1. (a)Engine cooling. Cool the engine during testing so its intake-air, oil, coolant, block, and head temperatures are within their expected ranges for normal operation. You may use auxiliary coolers and fans.
   1. (1)For air-cooled engines only, if you use auxiliary fans you must account for work input to the fan(s) according to § 1065.110.
   2. (2)See § 1065.125 for more information related to intake-air cooling.
   3. (3)See § 1065.127 for more information related to exhaust gas recirculation cooling.
   4. (4)Measure temperatures at the manufacturer-specified locations. If the manufacturer does not specify temperature measurement locations, then use good engineering judgment to monitor intake-air, oil, coolant, block, and head temperatures to ensure that they are in their expected ranges for normal operation.
2. (b)Forced cooldown. You may install a forced cooldown system for an engine and an exhaust aftertreatment device according to § 1065.530(a)(1).
3. (c)Lubricating oil. Use lubricating oils specified in § 1065.740. For two-stroke engines that involve a specified mixture of fuel and lubricating oil, mix the lubricating oil with the fuel according to the manufacturer's specifications.
4. (d)Coolant. For liquid-cooled engines, use coolant as specified in § 1065.745.