2010 VW Passat, 2.0T TSI engine. Generally an 80/20 mix of city/highway driving. I have been using the Motul 8100 X-cess 5W40 since I drained the factory fill at 1,409 miles. I have the oil changed every 5,000 miles or so, instead of the factory-recommended 10,000 miles. My hope was that the...