Sounds to me as though your engine likes that oil. Why would it be bad? That old 2.slow engine is low-tech enough not to require oil with esoteric, proprietary specs.
How often do you change your oil?
-Uwe-
Why would it be bad?...Well, only because it's counter-intuitive to me to be putting 40wt oil in gas engine in the winter. It's not really a big deal...the car is working fine now, and since you guys were discussing the finer points of oil, I thought I'd stick my nose in and ask. I'm just glad it's not burning it anymore, or throwing DTC's for the O2 sensor.
Oddly enough, I did stop into one of the local independent VW shops earlier on to ask about this oil usage, and the guy at the counter says "How much oil is it going through? A liter or two between changes?". I said yes, and he replied "Oh, well they all do that...you have to check the oil you know?". As he said that, he looked at me like I was an idiot because I somehow appeared to think that burning oil wasn't normal. Anyway, I'm all good now...LOL. I'm over it.
Since this car is mostly on the highway, and I'm buying this expensive oil, I've been running between 6000-8500 miles between changes. I often do 600 mile days...2-3 times a month, and then a little city driving in between, but not much.