This SAE Recommended Practice is applicable to oil-to-air oil coolers installed on mobile or stationary equipment. Such oil coolers may be used for the purpose of cooling automatic transmission fluid, hydraulic system oil, retarder system fluid, etc. This document outlines the methods of procuring the test data to determine the operating characteristics of the oil cooling system and the interpretation of the results. For information regarding application testing of oil-to-water oil coolers for heat transfer performance, see SAE J2414.