Dyson oil analysis from first two oil changes of 2015 VW GTI 2.0 liter gasoline turbo engine, DSG transmission, APR stage 1 ECU software, APR carbon fiber cold air intake. Posted with permission. Miles/time on 1st oil (factory fill, maybe Castrol Syntec 5W-40): 2889 mi / 6 weeks Miles/time on 2nd oil (Castrol Syntec 5W-40): 3781 mi / 3 months Current oil in use: Pennzoil Ultra Platinum 5W-30 Driving style and ambient environment: Sporty but car is never raced or tracked. City/hwy/trip length: 30% hwy, 70% city, average trip length about 10 miles. Location: U.S. Southeast. General comments by analyst: - Factory fill (allegedly Castrol Syntec 5W-40) doesn't have characteristics consistent with that type. - In general numbers are OK, but key lubricating qualities were depleted and oil needed changing at 2,889 miles. - 2nd oil change (Castrol Syntec 5W-40): Fuel dilution is key issue. Suggest trying different oil (various ones discussed), re-sample in 3,000 mi. Concern about deposit build-up over longer periods.