Mobil 1 15W50

[911/Q45]

I live in coastal CA(lows in the 30s-highs in the 80s) and have used Mobil 1 15W50 for many years. Any downside to that weight? How low a temp would it take before I had trouble with that weight? What kind of problems would occur when I did have trouble?

[PalmerWMD]

In warm climatesit's safe to run all year round since your lows are not so low.Bad effects of running too thick an oil would be excessive wear especially on the rings in cold startup, but I dont think your oil weight is not excessive.

But I see your temps are not as high in summer, as I thought the case would be for CA.In LA in summer the 15w-5o would probably be a good choice.

Actually if you wish to stick with MOBIL1, I would run 0w-40 all year round at your location.

MOBIL1 0w-40, used to be available only at MB+ Porsche dealers but now at many Autozones as well.Alternatively any group III or IV, 5w-40 will also give great service year 'round.

Fred..=)