This SAE Information Report details some of the equipment and procedures used to measure critical characteristics of automatic transmission fluid (ATF) used in current automatic transmissions. It is intended to assist those concerned with the design of transmission components, and with the selection and marketing of automatic transmission fluids for the use in passenger car and light-duty truck automatic transmissions. The information contained herein will be helpful in understanding the terms related to properties, designations, and service applications of automatic transmission fluids.