You'll never know the difference and neither will your engine,its compatable and the vis ranges are close enough that it won't affect that.RUN IT.bluevfr said:I accidently put 0.2 quarts of fully synthetic 15W-40 oil in my engine, mixing it with 2.7 quarts of semi synthetic 10W-40 I put in the day before :a2. Just wondering if this is a serious fuckup or is the engine good to go?
Not true Motul E-Tec 100 is a blend of Ester and PAO synth oils and Mobil 1 Red cap tri synthetic is a blend of 3 different synth oils.if you read the bottles they generally state somewhere ,compatable with all conventional and synthetic oils.there of course may be odd ball exceptions but all the major players are compatable.Way back in the bad old days when synth oil first came out it was a problem because many people at thet point in time(1970's) used gycol based oil,they do not use it any longer(haven't in years in fact).LifeLiberty said:I don't think I'd worry too much. but I've heard sumthin about mixing 2 different synthetics was bad because they won't mix together, they will separate. but I don't really know. check here is you are worried