What does ash content mean?
There is no ash in engine oil! Ash refers to Sulphated Ash which is the by-product of a laboratory method originally developed for evaluating the amount of detergent and known metal-containing additives in diesel engine oils. The amount of ash can indicate the formation of residues in the combustion chamber of the engine. That is why the precise determination of the ash content may be important. The laboratory test for sulphated ash measures ingredients such as anti-oxidants, anti-wear, soot and sludge dispersing additives but none of the dispersancy. The sulphated ash laboratory test does not tell you if a more or less effective detergent is being used and therefore ash is not a very good measure of an appropriate oil for a particular engine. My oil consumption has gone up since I changed to Shell oil. In most cases the high oil consumption is mearly a perception. However, any good oil like Shell Rimula X 15w-40 there could be a possibility of pil consumption particularly when used in
