Mélange, 20000 miles, rotary Mazda RX-8 w. 90000 miles

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This I had analysed to get a feeling if I would discard oil changes with the car, not for judging performance of an individual oil obviously. (Ro 80 rotaries in the end were said to not require them any longer it seems and although the Renesis' continuous exchange rate should be about half as high, with the more modern oils that's still what I'm trying.)
Main use overland, daily driver. Bought the car filled with fresh Mazda Original Supra 5W-30 and went on litre by litre with no filter change and several different products over the 31000 kilometres distance till "Oelcheck". Those were:

1l 10W-40 ATU

5l Kroon Polytech 5W-30 (PAO-OSP)

1l 20W/50 Eurolub GTS

5l Motul 5W-50 (PAO-POE)

3l Kroon Polytech 5W-30

1l 20W/50 Eurolub GTS


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Interesting. I haven't seen many rotary engine UOAs at all. Did this result help you decide whether to stop changing the oil?
 
Basically yes. At least I thought so. These engines are hardly extremely low in ppm Fe or Cr and these numbers can happen with comparable rides after less than one third of such oil mileage. Unfortunately I didn't opt for Acid Number testing in addition to BN, but I really had no fear going on after the lab report.

Then it got a short story when somebody killed the engine. I had been experimenting too much with alternative spark plugs and (three Kilometres from home and pulling them as planned for becoming safe again) the ceramics of one broke and took an apex seal with them. So it's awaiting repair or replacement. But even if restarting with a new engine I'd see how far I can get with only filter changes and occasional probing. That's not what I would pursue with other engines, only on this with its metering oil pump always infusing about a quart for 2000 to 2500 miles.

For the new oil I'm inbetween three main options.

-ending variety by going with plain Rimula R6 LME Plus
-going with its thinner FA-4 cousin Ultra E Plus to gain room for some irresponsable down- and upmixing with pure PIB or 2T heavy on PIB. Ultra E is not for mixed fleets, but the mixing ain't for any fleets anyway.
-going with Delo 600 ADF because of its very low ash path (also no SN or SP for mixed fleets)

After the report I'd gradually started blending some two stroke oils when topping up because i never managed to find any 4T containing much PIB (except one ancient msds of a RayleneBlend with less than 10% and probably not even available any longer).

A real need for three of these cars, but I'm content when the one is needing oil again.
 
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Sorry to hear of the engine damage. I hope you are able to get it fixed and back on the road soon!
 
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