Having just changed the oil in three of our family cars using a blend of Valvoline Syn/Conv. 5w-20/30 and Mobil 10w-30 oil, I needed to top off (a slight amount) in one of the cars and I used my Castrol (German made) 0w-30. Compared to the other oils it was like molasses in winter. I have enough of the GC 0w-30 for one more OC in the VW Golf 2.5L then I'll be using my stash of (18) 1 Qt. bottles of Pennzoil 5w-40 "Euro" formula for the next 3 OC's. I'm really curious how the two will compare! Advance Auto had a great deal on this oil. $35 less $10 MIR + Fram Ultra filter.