40 Protection of Environment 33 2014-07-01 2014-07-01 false Coastdown procedures for motor vehicles at or below 14,000 pounds GVWR. § 1066.305 Section § 1066.305 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Coastdown
§ 1066.305 Coastdown procedures for motor vehicles at or below 14,000 pounds GVWR.

For motor vehicles at or below 14,000 pounds GVWR, develop representative road-load coefficients to characterize each test vehicle. Calculate road-load coefficients by performing coastdowns using the provisions of SAE J1263 and SAE J2263 (incorporated by reference in § 1066.1010). Perform coastdowns at a starting speed as specified in SAE J2263, or at the highest speed from the range of applicable duty cycles. Use the same road-load coefficients for all duty cycles. However, if your test conditions are substantially different from the conditions represented by your road-load coefficients, such as cold temperature testing, you may use good engineering judgment to develop separate road-load coefficients.