This SAE Recommended Practice establishes a procedure for determination of vehicle road load force for speeds between 115 and 15 km/h (71.5 and 9.3 mph). It employs the coastdown method and applies to vehicles designed for on-road operation. The final result is a model of road load force (as a function of speed) during operation on a dry, level road under reference conditions of 20°C (68°F), 98.21 kPa (29.00 in-Hg), no wind, no precipitation, and the transmission in neutral.
Since the last update of J2263, industry has continued to gain practical experience. This revision reflects procedural changes and introduces new metrics to guide practitioners as they measure and determine vehicles road loads.