SloopJohnB@mac.com

The 30 or 40 means the oil has an SAE30 or 40 viscosity at 100C.

The synthetics ARE different....a 30 synthetic is thinner at 100C than a 40 synthetic.

5v/cyl

According to the owners manual using a 5w-30 synthetic oil is O.K. if a VW 502 approved oil is not available. It will run and not hurt the motor, but it is not optimal for engine protection according to Audi engineers.

The big thing for VAG and most other European automakers is the A3 rating of the oil. They don't care about the API #'s. For a oil to meet A3 standard it must have a HTHS (High Temp High Stress)rating of greater than 3.5. Basically it means it has a stronger film strength and is less likely to fail under extreme stress. M1 0w-40 and GC 0w-30 are the two easy to find ones that meet this in the U.S. out of the list of approved VAG oils. They are not expensive either.

2.7Lturbo

four words: shell rotella full synthetic

Just Me

I mostly agree. In warm areas i in fact prefer 10wX since it narrows the range and reduces the need for VIIs, on which have posted extensively in the past ( they are bad). STFA.

5w40 likely the best all around choice.

G

Just Me

good gosh, the rep could nto be wronger. regardless of whether its synthetic, refined dino, or olive oil, it is a specification that determines how thick it is and how strong the film is under shear.

The 2nd number is measured at 100 deg C. The first at 40.

In theory a wide spread is good - its thin when needed and thick when needed. in practice it doesn't work so well over time, so selecting a narrower range for the winter and another for the summer has some benefits.

G

uberwgn

That's right. And the mfr's written specific is far more specific than anything API has and you'd expect that, too.

More engine mfrs are turning to an explicit spec. The API standards are too broad for the Euro mfrs' comfort.

Just Me

I ran it in my 2.7 for 5 years and 80k miles. At the end the motor was absolutely perfect, used zero oil, etc.

However, they key is not to coke it - run hard and hot and shut down, allowing heat soak to coke the oil.

M1 0w40 shears down to roughly 5w30 anyway.

G

AUJ

Been a M1 0W-40 guy for awhile on both the Audi and Porsche. However, looking at some forums dedicated to oil analysis is leading me to believe Valvoline SynPower may be worthy of a trial.

http://www.bobistheoilguy.com/forums...309815&fpart=1

AUJ

Meets VW 502 and 505. Hmmmmmm.