40 CFR § 89.327
Charge cooling
June 9, 2020
For engines with an air-to-air intercooler (or any other low temperature charge air cooling device) between the turbocharger compressor and the intake manifold, follow SAE J1937. This procedure has been incorporated by reference. See §89.6. The temperature of the cooling medium and the temperature of the charge air shall be monitored and recorded.
[59 FR 31335, June 17, 1994. Redesignated at 63 FR 56995, Oct. 23, 1998]