I don't recall this being discussed on the Fly Rotary list in the recent past.  So, here goes...

What is the consensus regarding oil change intervals for normally aspirated rotary powered a/c, assuming Mobil 1 and a high quality oil filter.   I want to err on the safe side, but with a 12 quart capacity, we're talking about $100 per oil change.   I don't want to damage my engine/psru, but I also don't want to dump good oil either. 

Mark S.