This SAE Recommended Practice was developed by SAE, and the section “Standard Classification and Specification for Service Greases” cooperatively with ASTM, and NLGI. It is intended to assist those concerned with the design of heavy duty vehicle components, and with the selection and marketing of greases for the lubrication of certain of those components on heavy duty vehicles like trucks and buses. The information contained herein will be helpful in understanding the terms related to properties, designations, and service applications of heavy duty vehicle greases.