This SAE Recommended Practice is applicable to all heat exchangers used in vehicle and industrial cooling systems. This document outlines the tests to determine the heat transfer performance under specified conditions. Purpose This document is to provide a test guideline for determining the heat transfer performance of a heat exchanger under specified design conditions. Objective To determine and document the heat transfer characteristics of a heat exchanger. This document describes a system to flow fluids through the heat exchanger at specified rates and temperatures@ and describes and recommends a procedure for documenting the results. The procedure may be varied to match existing equipment and methods.