Did an oil change today and actually measured what was drained. It was shy of full by about what the oil filter would hold. This is at the end of a 4,000 mile OCI. The engine has never once seen any synthetic or high mileage oil, and just the standard mid-range oil filters and 10w30 dino juice. I put some Mobil 1 HM 10-40 full synthetic in it today for the first time.

What's strange is that I am sure it used to burn a good bit of oil by 4,000 miles, but I did a PCV valve replacement not too long ago, which might have reduced oil consumption for this oil change interval.

Unusual or are these engines just that good? Thing doesn't even leak a drop of oil at all at over 320,000 miles.

 

All engines burn some oil. At 320k w/o an overhaul I'd think you'd notice some loss. Was the dipstick level unchanged from the start of the 4,000 mile run?

 

I never had a 20/22r that didn’t use some oil. Count yourself lucky.