SAE J2985-2019 PDF

Scope: "This SAE Recommended Practice covers transfer cases used in passenger car and light truck applications. Transfer cases are of the chain@ geared@ manually and electronically shifted types although other configurations are possible. The operating points (speeds@ temperatures@ etc.) were chosen to mirror those of the United States Environmental Protection Agency Vehicle Chassis Dynamometer Driving Schedules (DDS). Purpose To provide a common means to consistently measure and quantify the speed-dependent parasitic loss (""spin loss"") characteristics of transfer cases. "

SAE J2985-2019 history

2019 SAE J2985-2019 Definition and Measurement of Transfer Case Speed-Dependent Parasitic Loss
2014 SAE J2985-2014 Definition and Measurement of Transfer Case Speed-Dependent Parasitic Loss