Greetings. I need to clarify a doubt I have about premix... I own an 1994 FD completely stock. I purchase this car recently with only 47, 357 miles. The engine has never been rebuild.

I don't use my car for street racing or track. I only use it for weekend driving and once in a while for casual commute to work during summer and now fall season.

I'm using Royal Purple engine oil... since the car is stock... meaning the OMP is active... do I need to premix since I'm using synthetic oil? I read previous posts and a few other members mentioned you can do both... also others mentioned you need to do premix if using synthetics... but I just want to clarify. Right now I'm not using premix.

Again, I know that I can just disable the OMP if I want but since I'm not using my car for extreme driving or street racing... what would be the best practice to follow? Thanks in advance.

 

Congratulations on the new car!

Keep the OMP hooked up and working. I would (and do) also premix in with your gas. It is cheap insurance if your OMP ever fails.

I use this:

Premix at Idemitsu Lubricants America Corporation

 

Two things:

1) stop using synthetic oil, it is not recommended with a rotary engine (https://www.mazdatrix.com/faq/synthetc.htm). Use idemitsu oil.

2) your car is fine if the omp works and you are using conventional oil. If you want to premix, use idemitsu pre-mix (no it is not the same as the oil I said in part 1, they make a separate premix.) dilution ratio is 1/2 Oz per gallon or less with the omp operating.

 

That's hardly a certainty. This is a topic that will be debated until the end of time.

This thread has some good arguments either way, its probably worth a read if you're curious:

https://www.rx7club.com/new-member-r...il-no-1037626/

Ignoring the entire holy war of conventional vs synthetic oil, my personal opinion is that with how often I change my oil on a rotary car, its not worth the money, I just use conventional.

+1 on the idemitsu premix oil. That is what I use on both my FD and my RX8. With a working omp on a FD you don't technically have to premix, but I still think its a good idea just in case. The stuff is cheap, and its insurance that everything should be getting lubricated.

Also, the sohn adapter is pretty cool. It gives the OMP its own oil reservoir so you can run whatever oil you want for combustion chamber lubrication, and whatever oil you want for your engine internals.

 

Thank you all for your feedback and recommendations. I didn't want to start a debate about a topic that is more than covered in this forum.

The reason I'm using synthetic is because the former owner already had synthetic in the engine and I didn't want to change to conventional since I wasn't sure it was OK to do so.

My first choice if I change to conventional will be Castrol GTX since is highly recommended in this forum.

Based on the already covered discussions about synthetic... I decided to keep using synthetic. Right now I'm using Royal Purple due to was locally available... but already plan to change to Idemitsu on my next maintenance routine since I need to order online. I will add the order for the Idemitsu premix too tonight!

Also, I'm going to do some research about the OMP adapter... sounds interesting.

Again, thank you for the recommendations and looking forward to learn more.

 

 

*You CAN pre-mix at about .5 oz. @ gallon WITH an OMP. It doesn't hurt for a little extra lubrication of the housings and hard seals, but if you have emissions testing in your area it wouldn't be good. And probably NOT an issue, but I'm not sure about long long term effect on the stock cat.
*You CAN continue to use RP synthetic. It performs better in the extreme heat of the turbos and won't cause any issues. There are others and this is a tired debate. But if you wanted to switch back to conventional oil there wouldn't be a problem either.
*You CAN NOT "just disable" the OMP on the stock ECU. That will cause LIMP MODE. No spark advance and fuel is cut if vacuum isn't seen at the intake manifold. Not too much fun on a turbocharged car.
*And I agree with overkill on new plugs with an oil change. But change intervals should be closer together than in other cars due to the fuel dilution and high heat conditions alluded to by RCCAZ 1. Because you're changing oil more often, it's one argument against synthetic, especially the high priced boutique oil like Indemitsu. But the choice is yours. It's not gonna void warranty.
*The Rotary Aviation OMP adaptor is a nice piece, but there are packaging issues with the reservoir, especially if you want to remain stock. And you MUST remember to refill. It's also not a walk in the park to install with the engine in the car.

 

 

Thanks for all the valuable information!