This procedure incorporates a modified driving cycle replicate of consumer operation as contained and shown in SAE J1082b (January@ 1979) and which is run on a suitable road or test track. The procedure yields cold start and warm-up fuel economy values indicative of consumer level at the ambient condition of the test. Within referenced limitations@ the procedure can be utilized to be determine the fuel economy differential among vehicles or between vehicle changes. Purpose-This recommended practice provides uniform testing procedures for measuring the cold start and warm-up fuel economy of light-duty vehicles (motor vehicles designed primarily for transportation of property and rated at 6000 lb or less).