I have a 2017 Subaru Outback 2.5i Last oil change was with Subaru 0W20 synthetic with a Subaru filter. Current oil change is the same. I finally got a Fumoto valve installed so I will start doing my own oil changes(36/36 warranty is up). I am not sure if it's just in my head or if the engine was actually running rough after 5900 miles on the oil. Engine seemed to idle quieter and smoother after the oil change. This makes me wonder if Subaru oil is only designed up to 6k like their cars are rated at, or is the oil over engineered like M1 for 10/15/20k OCIs? I'm want to keep the engine protected Incase I'm ever in a pinch and need to go 500-1000 miles over. The only time I've went over 6k was when I was using royal purple and Mobil 1 filter, and it was only 80 miles. I did not notice the engine running "rough" then. Engine has just started to burn some oil at 36k. About 1/2 quart every 1500 miles. I plan on using valvoline syn power or Mobil 1 extended performance next.