This document covers evaluation techniques for determining the power consumption characteristics of engine driven hydraulic pumps used on heavy-duty trucks and buses. The testing technique outlined in this SAE Recommended Practice was developed as part of an overall program for testing and evaluating fuel consumption of heavy-duty trucks and buses. The technique outlined in this document provides a description of the test to be run to determine power consumption of these engine driven components, the type of equipment and facilities which are generally required to perform these tests are discussed in SAE J745. It is recommended that the specific operating conditions suggested throughout the test be carefully reviewed on the basis of actual data obtained on the specific vehicle operation.
The purpose of this document is to expand on the scope of the existing SAE J745. All of the specifications and apparatus utilized in that document for construction and industrial machinery can be utilized in this procedure. Information presented in the manner outlined as follows can be used to compare the hydraulic power requirements of fixed or variable-displacement pumps and estimate actual power consumption after the vehicle duty cycle has been determined.