1 quart oil or more per 1,000 miles go through the PCV system as oil vapour?
This would explain why in hot summer days I see negative fuel trims at idle + low load cells! See my thread "Fuel trims suddenly change?"
http://teamzr1.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=639#Post639Since I performed an engine cleaning + decarb procedure + orifice instead of the PCV valve the problem is solved
You have reason about the oil consumption in summer: I use a synthetic 5W30 oil and I need to add a quart every 1500 miles.
We don't have 10W30, the next quality oil 0W40, then 5W40, 10W40, 15W40 and 5W50.
What do you suggest?
The lower temperature in winter is 5F, the highest in summer 95F.