They might be similar in running temperature but something tells me there is a reason the rx-7s came with such a large oil cooler where many piston engines simply do not.

Yes they put a lot of thermal energy into the oil, that's what the oil cooler is for, but as long as the temperatures aren't any different, then the oil won't care. There's plenty of piston engine car with oil coolers too you know.

The only problem with running diesel oil that I have found so far would be foaming of the oil. There are ways to get around this however.

additives

however, the Renesis continues to have trouble with normal oils foaming. It's give and take, there's still ways to keep oil from foaming.

I use that in my diesel didn't even think to stick it in the 7

I sell oil as well as fleet service. Archer Oil out of Omaha,Neb. I run 20/50 hi torque in my turbo and 5/30 syn in my race n/a engine. Most diesel oils are for diesel engines with no egr system. The late model diesel motors have this egr sys as a fed requirement. Do more home work. get info from more than 1 salesman. The oil company that I represent has oil analysis. I've asked the folks that have been testing for years. Do your home work before you commit.

What do you expect to gain from running diesel formulated oil that couldn't be gained by just running a heavier oil like 20w50?

Personally, its not like the rotary suffers from any kind of premature bearing failure or anything that would require re-thinking the contents of the lube system - outside of modding passages and teardropping orifices on the e-shaft etc.

But I highly doubt its going to kill anything either?

Idemitsu makes a synthetic engine oil specific to the rotary engine. They took into account the OMP when they designed it. I've never used it. I run 10w-30 Mobil1 and have a seperate tank for the OMP system that injects the Idemitsu oil.

I think the one thing to really be condidered when choosing engine oil is the ability to cope with fuel dilution. Alex has an MS6, with DI which apparently has some issues with fuel saturation in the oil. He runs Shell Rotella for this purpose

My good friend ONLY uses Rotella in his Subaru's (STi and Turbo Legacy). Apparently they all swear by it as well.

I never thought to use it in a rotary though.

Really...

REALLY...

Do you think we're stupid enough to listen to some saleguy???

Please go away troll.


-Ted

:smilielol5:

It really comes down to ash content. CJ-4 Has much less ash content than most oils I've seen from BITOG.com. Less ash, means less chance of pre-ignition events occuring within a given time period.
It's not the bearings I'm concerned about, it's the pre-ignition factor. Since the car is injecting oil into the combustion chamber the ash content of the oil becomes very important. The less ash (under .5%--I think, it's been awhile since I looked), means less chance of carbon build up and less chance of pre-ignition. There is a discussion on ash content and oils that were discussed in the Rotary Engine forum, which I'll link shortly if wanted.
See above.

Ash content would be less of an issue if running aux injection since the engine is always being steam cleaned. I had been running mobile 1 15/w50 which was designed for performance cars that needed extra antiwear additives. I'm not sure what the ash content was but it seemed like the oils with extra antiwear had more ash. Walmart stopped carrying the oil i used and it seems like all the oil formulas are going green which have much lower antiwear properties. These oils could cause us to see more bearing problems pop up. Not to mention our expensive turbos can use a good quality oil. At least the desiel oils don't appear to be removing all the stuff giving extra protection. I'm still debating on what oil i want to use. I like synthetic because it seems to run a little cooler, and doesnt coke up the turbo bearings. But it's also more expensive, so it may be just as well to go back to "dino" oil and change it twice as often. So many choices. If you google it, you'll see the topic of antiwear additives is an issue on tons of car forums.

Really a good zinc package integrated within the oil should be all you need. The additional additives increase foaming. The base oil itself is what you need to worry about: ash content is derived from there. Let me dig up the link.