Originally posted by VeeDubb: I prefer Synpower 5w-40 over M1 0w-40. Wear numbers tend to be better with Valvoline. Having said that, I will be running M1 5w-30 because I don't like the shearing that occurs with any 0w-40 or 5w-40 oil. You can go to fancier brands like Lubro-Moly or Pentosin 5w-40, but in a couple of analyses on Lubro-Moly, it also sheared to a 30 wt. There is one analysis with Pentosin in a VW W8, and that oil barely remained a 40 wt even in a non-turbo with an 8 quart sump. Hate to see what a 1.8T would do to the oil. Who knows, maybe Synpower will hold up okay in the V6 since it has a large sump and no turbo. Only way to know is to try it and do an analysis.
Originally posted by mardigan: I started out by looking for the Castrol 5w40 but have been unsuccessful at finding it anywhere locally. I also think the Pentosin would be a great choice, I just wanted to find something that was available locally instead of paying for shipping everytime to order it online. Anyone know of a place that would stock either of these oils in the Salt Lake, Utah area? Edit: What drain interval are you using on the Pentosin?
quote:I'm not worried about shearing because of the viscosity per se. Otherwise, I wouldn't be running a 5w-30. I don't like shearing because it implies VII breakdown which leaves varnish in your engine over the long run. The M1 5w-30 stays in grade even in the 1.8T. That's why I use it. If it lost 15% of its viscosity, I wouldn't use it because it is probably depositing gunk into my engine (even if wear rates are completely unaffected in the short run). p.s. there is no question that the 0w-40 shears in the 1.8t. Do a search on used UOAs. The only question is whether it will shear in the V6. Not enough data to confirm. [ February 10, 2004, 12:48 PM: Message edited by: VeeDubb ]
Originally posted by MikeW: [QB] Even if it sheers, which is questionable at best, the M1 0w40 stays at a high 30. Even then, it's running at a higher vis than the 5w30, which starts out as a lowish 30.