And no, it doesn't feel any more or less smooth (it was always smooth), and fuel economy is about the same or possibly marginally better than the QS synthetic. Even though the German Castrol is not rated as an energy conserving oil, I can't see a difference. Actually it should help alot in the winter. This is the factory fill oil my car was built with, and in Europe they are running 30,000KM oil change intervals! Soon I will run the 15,000KM interval spec'd for North America. Great website everyone!