Originally Posted by 742
The VW 1.8T calls for VW 502 oil, which is a tough standard to meet and is always synthetic. Favorite oils are Mobil 1 0W-40 and Castrol Syntec 0W-30 – just like here in BMW land.
The turbos are water cooled, and there is flow with the engine shutdown.
That said, the sump is small and some owners/dealers did try to run dino. However it appears that even with the proper synthetic the engines will sludge (actually the problem is not "sludge" in the traditional sense) if the oil is left in too long or if the crankcase ventilation system is not working correctly.
The most interesting part of this mess is that it is a North American problem. Subtle differences in operating environment, fuel standards and who knows what else can have big impacts on maintenance requirements, occasionally to the surprise of the engineers. And this example shows how it can take time for these issues to surface.
yeah, it's stuff like this that makes me want to change my oil in between the cbs intervals