robot808

The mechanic that was going to rebuild your engine suggested that oil?
Man, it's a good thing that he didn't start the work. I can't see that going well.

dprantl

Posts of people using the wrong oil viscosity keep coming up more and more. I wonder why anyone would think a 30w oil would be okay in a 928... where does someone come up with this? When you buy a car and are about to change the oil for the first time, does it not occur to you to check what its crankcase is supposed to be filled with before you go out and buy the same oil you put in a Ford Explorer? Sorry, but it is such a shame to destroy a 928 engine in such an ignorant way.

Dan
'91 928GT S/C 475hp/460lb.ft

gearz

^^^^^^^^^^
My Explorer uses 5/30w. I've got 150+K on it and it runs great. God that stuff sure is thin though; can't imagine using in on my S4.
It's like comparing water to molasses.......

mi650

My manual lists 5w-20, 20w-50, and just about everything in between.

dprantl

Well, I guess part of the problem is the really dumb pictogram that depicts which oil to use in what temperatures in the owner's manual. It really does not make much sense at all, but even in that graph 5w-30 oil is shown to not be used when it is warmer than 32 deg F ambient (5w-20 when not over 14 deg F!). 10w-30 should not be used if temperature will go over 68 deg F, but then it has a "fuel efficient oils" section at the bottom, what the heck is that? Then at some point it says to check with your Porsche dealer, who I bet will recommend a synthetic 5w-40. Anyway, to be on the safe side, 20w-50 listed in there is supposed to be good all the way down to 14 deg F, so IMO a 15w-50 is the best option for most places since it should be good for somewhere close to 0 deg F.

Dan
'91 928GT S/C 475hp/460lb.ft

mi650

Dan, that makes sense.

I'm wondering how much the Lucas upped the viscosity. It probably took me 5 minutes to pour a quart in. That stuff is thick!!