Mobil 1 viscosity
 

My 2.7T has 70K miles, would you recommend Mobil 1 0W30 or 0w40?

M1 0W-40 is approved by Audi. M1 0W-30 isn't..

I'd recommend 0w40 unless you live with cold winters, then 0w30 is great for winter use.
 

M1 0w30 flows much better than M1 0w40 when it's zero degrees F outside and had good hot engine protection. I've used it and it worked well; turned in a great UOA (used oil analysis.

But for 3-season use, M1 0w40 is superior. It's rated ACEA A3. Like M1 5w30 & M1 10w30, M1 0w30 is rated ACEA A5 as it has a lower HT/HS (high temp & sheer rating) number than the A3-rated oils. I buy mine at AutoZone.

The best oil I've found so far for the 2.7t is the Made-in-Germany Castrol Syntec 0w30. It MUST say "made in Germany" on the bottle. It's rated ACEA A3.

Mobil 1 0w40 year round
 

Or Made in Germany Castrol Syntec 0w30; this is [supposedly, but i'm 99.99999% sure] the same as Castrol SLX, which comes factory with the Audis.

The Audis {or rather many auto makes and service bays] in europe use SLX for really long drains, something like 30,000km, of course with appropiate top ups to replenish additives. The Mann filter can go up to 30,000km as well.

Re: M1 0W-40 is approved by Audi. M1 0W-30 isn't..
 

Thanks, think I'll get 0W40 at the next oil change, I live in CA so it never gets that cold anyway - and extra protection for the turbos in summer would be good.

Wish I could fine the article where a guy ran his car on Mobil 1 for 60,000 miles without changing it, analysing the oil regularly. There was no change in viscosity at 60K though the acidity and particle count was getting high.

Mark

Similar, not for 60,000 miles but its up there
 

its a long interval for sure! Used a different Mobil 1 wieght, but with proper UOA and topping up you can make it go the distance.<ul><li><a href="http://neptune.spacebears.com/cars/stories/mobil1.html">Here</a></li></ul>