Changing Brands of Oil in my V.W. Tiguan

May 17, 2009
N.H, U.S.A.
Your engine didn’t like heavy oil, light oils etc. It is engine, not oils. You got lemon that had issues that were less obvious with certain oils, and that is it.
I've seen this across many platforms and designs and have dealt with it with viscosity tailoring.
Originaly started it on the Subaru FB25. Idemitsu was at the very light end of the 0W20 spectrum with KV40 back then in the mid to high 30's. Putting Valvoline or QSUD in that sump was like going up a grade. and the destructive sounding and feeling hot engine racket was gone.