PalmerWMD wrote: ↑
Tue Feb 15, 2022 10:24 pm
Depending on your driving change more frequently within your common sense.
In Europe where 10,000+ mile oil change are de rigeur (because they are very expensive and manufacturers get a lot of pressure to think about the environmental impact form oil changes) technicans have been seeing problems from that.
I was just watching german master tech for Mercedes complaining on the internet that fuel dilution from too many short trips was making the oil too thin to work properly.
That's the key, trip length. The PCV system is there to evacuate blowby, but there's no way to make the piston and cylinder wall clearance any tighter when the engine is cold. On direct-injected vehicles that results in a lot of "wall washing" until the car warms up fully, and if it never does, the PCV system is eventually overwhelmed and the oil is contaminated. Forget the "factory interval" and judge yours by your car, climate, and driving habits.