JASO M331:1991 (Nissan VG20E)

Test Method Summary
The JASO M331:1991 specification test evaluates the low and medium temperature detergency of lubricating oils for automobile gasoline engines. Depending on the oil quality, the test duration is either 200 hours (regular grade or equivalent to API SE) or 300 hours (premium grade or equivalent to API SG).

Test engine Nissan VG 20E (gasoline)

Test Fuel Class 2, as specified in JIS K 2202, but the fuel must not contain any gasoline additives Test conditions One cycle consists in the following 3 stages:   I II III time (mins.) 24 24 12 speed (rpm.) 800 1800 3500 load (Nm) 20 99 99 Oil temp (oC) 522 962 1172 (temperatures are also specified) The oil level is checked every 25 cycles. Test duration 200 or 300 hours depending on the oil quality Measuring items Includes .... rating of sludge and varnish / blocking of oil strainer / oil consumption / wear / deposits on valves / deposits in combustion chamber / used oil analysis