Just wondering if the additives that keep high mileage oil from burning more etc are better for a rotary then standard mileage oil. In other words... if a rotary engine has 80+,000 miles would it be better to use standard Castrol GTX 20-50 or Castrol GTX high mileage 20-50?

Ive been using high mileage in my 145,000 mile GXL for a year and a half and it never smokes and hardly consumes any oil at all. I put standard GTX oil in my "new" 84,000 miles Sport and it seems to smoke a bit. Its not bad but you can definately see a small bit of haze. BTW the car sat for 8 years and I just got it running a couple weeks ago.

 

Regular. High mileage is designed not to burn, you want it to burn. But that's probably just less burning as a result of less leaking. I doubt it makes much of a difference, though. IIRC in general (for piston engines) you're better off w/o the high mileage stuff unless you have problems with oil consumption.

I'd run the 84k mile sport a while longer and see if it still smokes, then figure out the cause from there.

 

I used regular GTX 20-50 and everything ran cool. 89 GXL 118K miles.

 

Avoid "high mileage" oils in rotary engines. Too much zinc (which forms deposits) and other additives that are not really needed.

 

Castrol 20w-50 works fine for me and alot of other people

 

I think many high mileage oils have addatives which are designed to make the soft seals swell and leak less as well, don't see much need for that in a rotary.