Originally Posted by Swissman564

Putting any product from Walmart into an Audi just does not compute. That aside, my father is the best hands-on mechanic I have ever known. Retired now, he was a service manager for about 15 years after learning his craft and then a partner-owner for 20 years in a dealership where he oversaw the service and parts departments. He has always sworn by the Castrol brand and that's good enough for me. I use Mobil 1 because that is what Audi recommends.

Originally Posted by Swissman564

Putting any product from Walmart into an Audi just does not compute. That aside, my father is the best hands-on mechanic I have ever known. Retired now, he was a service manager for about 15 years after learning his craft and then a partner-owner for 20 years in a dealership where he oversaw the service and parts departments. He has always sworn by the Castrol brand and that's good enough for me. I use Mobil 1 because that is what Audi recommends.

Originally Posted by Vicl

Let me add few things.

When I posted this topic a while ago I also did quite extensive research. I live in Toronto, Canada and one of the research items was oil availability. From quite a few brands I found Mobil 1 0w40 and Castrol 5w30 are widely available (Mobil 1 0w40 in Canadian Tire and Castrol in Wall Mart and Canadian Tire).

But from all research I've done I found Castrol is not true synthetic oil. I even end up writing it to Castrol and asking why they have "synthetic" on the label. It is really Semi-Synthetic blend. From another hand Mobil 1 0W40 is true synthetic oil and it meets long life specs (Castrol does not). Theoretically we can let such oil "sit" for 2 years unchanged and let it run for much more miles. I'm not planning to do that, but at least I trust a little more to such type of oil.

In other words for me the choice was clear just based on those facts. In addition to that Canadian Tire every so often does the sale events. I always buy my oil with 35% discount and it costs me around 8 something dollars + tax.

NOTE: ONLY Mobil 1 0W40 meets and exceeds (long life specs) the Audi requirements. The link posted above by Mishar in WM is not referring to that oil and I would not try to use it.

Originally Posted by mishar

0W30 is perfect oil for A8 especially driven in North America. 0W40 would be a bit better choice for summer driving on Autobahn racing BMW's and Porsche's.

Internet "research" can be quite deceiving blurred by endless marketing and ordered "analyses". Here is all that matters. Brand names are not that important.

Of course we can promote every oil change into a scientific project but it is more for a fun than it really matters.

Originally Posted by bmwm750

Ehhhh yes and no. The problem with many of the newer oils, especially for gasoline engines, is the low levels of ZDDP (important for bearing film and thus bearing protection) caused by the requirement to certify emissions components to 100k (mainly the cats). Also, with all the influence from "energy conserving" comes less protection.

Now, do any of these issues play out in the first 200k miles of a car's life? Maybe, maybe not. But, for me, I'll gladly pay a small bit extra for a bit of added peace of mind.

Originally Posted by mishar

Yes and no. All of them have less ZDDP in order to protect catalytic converters and so on. So brand name and viscosity wont change anything there. On the other hand, our engines with roller rocker arms do not really need that much ZDDP.

By the way, I use 0W30 Red Line. 0W is the most important because it marks cold oil viscosity and that's where majority of ware and damage happens. Thicker oils resist flow and diminish lubrication. 30 compared to 40 saves some fuel and lubricates just fine. Red Line because I love it For me price is not that important because I change it once a year.