This test method is designed to evaluate the ability of an automotive crankcase lubricant to inhibit the deposition of sludge and prevent wear in gasoline engines when operated on a fuel that is prone to generate such problems. Lubricants intended for use only in gasoline engines and those intended for mixed fleet application covering both gasoline and diesel engined vehicles may be evaluated by this procedure.

Results of tests run under this method are presented on a merit rating scale from 0 (extremely heavy sludge) to 10 (clean). Certain parts of the engine, the rocker cover, cylinder head, cylinder head front cover, timing chain cover and sump are rated individually and an average sludge rating is calculated from these separate numbers.

Lubricants giving satisfactory performance in these test, and meeting the other well established performance requirements, will give enhanced protection against the deposition of sludge when utilized in four-stroke gasoline fueled vehicles in both normal and severe service.