This SAE Recommended Practice applies to the laboratory measurement of rolling resistance of pneumatic passenger car, light truck, and highway truck and bus tires. The procedure applies only to the steady-state operation of free-rolling tires at zero slip and inclination angles; it includes the following three basic methods:
Force Method--Measures the reaction force at the tire spindle and converts it to rolling resistance.
Torque Method--Measures the torque input to the test machine and converts it to rolling resistance.
Power Method--Measures the power input to the test machine and converts it to rolling resistance.