We bought a new Camry in 2016 and they included the maintenance plan till 75k. 10k intervals for oil change, it now has 100k on it and uses zero oil and mileage has actually improved. I now do my own oil changes using Mobil 1
2008 Duramax has 350k on it, 10k interval using Wix and rotella T6. It will be a quart low at each change. Mileage has slipped about 2 mpg in the last year but still hanging around 17-18 mpg
