What oil do you all use - it is my understanding that the new Mobile 1 15W50 will give you a good level of protection. Much better thatn the watery thin 0w50 or 5w50. I am talking about in warm (+75degree) weather.

What is the concensus?

I live in Toronto climate...

0w 40 Mobile 1 is what the dealer suggested for me

Help your engine last longer and use the 15w50.

I think it might be relevant what engine it is that you're putting it into.

I'm not sure what oil AG was recomending for the M96 when it came on the seen in 98........but when the Turbo was launched they had no problem specifying 0W-40.......of course the 2 engines are significantly different.
My AMG, same year as Turbo, came out with same recomendation of 0W-40.

0w40 should not ever be used in any engine in hotter climates. Has nothing to do with what is approved or not. With engine oil of 220F and above, the 0w40 will not properly protect your engine. Even worse when oil gets to 240, 250 etc. Want to increase your chances of bearing wear that will cause the crank to move offcenter??? Stick with the 0w40. What happens when the crabnk moves out of spec?? RMS leak!

Has RMS leak been an issue on the Turbo also?

0 40 mobil 1...

No

I would be interested in what Stephen has to say about this. Appearantly the emerging "Crank thrust bearing issues" would suggest something other than 0W40.

The cause of the thrust has been established not to have anything to do with the weight of the oil. Keep in mind people that the oil acts as a hydraulic function for the valve train. This is something that Pete and I will agree we disagree. Porsches recommendation to run nothing more than a 5W has to do with the ability to run the tappets and the cam adjuster. I have documented. Bottom line is I build a lot of these motors and have data to support or not support my findings. At the end of the day I personally do not run 0 anything, rather the approved heavier weight oils from Porsche. I see to many failed tappets and adjusters to do other wise. There are always exceptions to the rule as 1999 will point out.

So Stephen, if you do not run "0" anything in your car, what viscosity are you running, 5-50? I was thinking of switching to 5-50 from 0-40. Do you agree?

I would also like to know.

Well, now I'm confused (not a rare condition for me). I thought the first number referred to viscosity on start-up - the lower, the easier flowing at lower temps. and that the second number referred to the ability of the oil to protect at higher temps.

Your comment 'I don't run 0 anything' makes me think I'm way off base?

I like Mobil 1 5w40 Truck and SUV. It has a lot more antiwear additives (by elemental analysis) than the new 0w40. You can also find it at Walmat for $20/5qt.

Just spoke with a Porsche race mechanic and an "oil expert" at Mobil, both agreed that 0w40 is the recommended oil for Porsche. Both said 0w-50 and 5w-50 are better but hard to get in the USA. The lower number lets the oil circulate thru the oil pump and system better according to the experts, and the higher number (50) gives better hot protection. We should find out how to get a group buy on 5W50. Apparently Mobil says they get it for the Peske team. 15W50 is ok in hot climates, but should never be used in cool climates or run hard in a cold engine.