StealthTL

iTrader: (1)

The reason that rotaries and synths don't mix is the huge 'O' rings around the housings - early ester and amine based oils would eat Buna N and Viton for breakfast.

First generation Mobil 1 was the oil that ate the seals out of my first rotary, in 1976.

Easiest for Mazda to just say 'no synths'....

ShellDude

iTrader: (12)

cool... another oil debate!

MazdaManiac

iTrader: (3)

Nope. No debate. Stealth nailed it.

9krpmrx8

iTrader: (46)

Yeah, while my recent failure (coolant seal) was no fault of the oil I use (Mobil1), I will probably just run Castrol GTX 40W in the new one since the one motor i did have that made it to 74,000 ran Castrol GTX 10W-30.

paimon.soror

iTrader: (15)

^^ Agreed (with MM), the point of this thread was for me to just get edumakated on exactly where carbon forms just so I can understand why the heck I am redlining my car everyday (not that I am complaining lol)