Just bought an 88 rx7 and I have been reading about oil changes and premixing. My question is that with premixing with idmatsu oil. Its Synthetic ,but with regular oil changes people are saying not to use synthetic oil. So I'm confused about premixing with synthetic and not to use synthetic with oil changes.

 

Please post any further Threads in their appropriate section as this was moved from a NON TECH section.

your Oil question has pretty well been beaten to death so Instead of members getting pissed and posting repetitious answers the Onus is upon you to seek the info that is already posted.
There are so many "agree to disagree" comments that you have to sift through the Fly **** to get to the pepper.

 

lmao my bad

 

Yes..you are..you are Bad......Spank.......now that's 20 bucks like downtown!

 

From the factory manual, Mazda recommend to use mineral oil only on all generation RX-7 (and maybe on RX-8 too). This is reasonable in the past because some seals in the rotary engine are made of soft rubber with low vulcanization degree. And synthetic oil at that time contained some ingredients (mostly fatty acid ester) that would cause those rubber to expand and break. New synthetic oil with improved formula contains less waxy ingredient and performs better at high temperature. I personally recommend to use Royal Purple or Idemitsu oil. (The latter one is testified with the victory of Mazda 787B) When you are shopping for Idemitsu oil check whether it is "Idemitsu Racing Rotary Engine Oil" or "Rotary Premix". You probably want both.

For more technical sources, here is a SAE paper on the subject. Be mindful it is for racing application.

SAE Technical paper series 922375
The Development of Lubricating Oils for Rotary Racing Engines
Takao Yabe, Toshihiko Arai, Shoji Aoyama, Masayuki Oshima
https://www.sae.org/publications/tec...ontent/922375/