Something is wrong with a dealer who insists on using the incorrect viscosity recommended by the manufacture. If the manual and oil cap show a viscosity that should be used then I would insist on the dealer putting the correct grade in. This idea of letting a dealer continue to do what they want and not the manufacture by saying is NO BIGGY or it doesn't matter is wrong. A sloppy greedy dealer trying to save $$ at the customers expense will not be my dealer. Ed