deemed to be binding both within the warranty period, but especially post-warranty. An
engine malfunction may be due to unsuitable use of fuels and lubricants, resulting in a
decrease in lubricating performances and protection of the oil. On the other hand, the wear
degree and wear nature of engine lubricant can provide clues related to possible engine
faults, for example: leaks for the combustion chamber, incomplete burn of fuel, improper …