Hello, I would like to make an oil change with my 928 (model 1979). For this I bought 7 liters “Motul 15 W – 50” (Specification according to operating instructions / 6.5 liters incl. filters are required). When buying I also told the car parts dealer that it should be for a Porsche 928, model 1979. But now I have seen on the oil bottle that only manufacturer approvals of VW and Mercedes are given. Now I ask myself whether I can fill it in without hesitation? (I have g) What to do, then? Greetings, Thorsten