gotorx7

Well, the story as I hear it is to NEVER use a synthetic in a Rotary, as the deposits left behind in the combustion chambers are a BAAAAD thing! Mineral Oils just burn off completely, hence no problem.

The Owner's manual from my '97 SPECIFICALLY says not to use synthetics, and despite rumours, I have NEVER seen anything from Mazda which states differently.

Personally I use Pennzoil 20-50w, but the oils we get here in Australia seem to be different from what you guys get in the U.S. (Pennzoil is evidently manufactured by Mobil here, and Pennzoil add their own blend of additives/colouring).

gzon

The GTX3 is castrols best mineral oil, I ordered a 25 litre can yesterday and got a good price, 4 US$ / litre.

I have used this oil since my first car and really loves it. Its the best mineral oil I have ever used.

rotorbrain

think about that now. most affordable cars come with mineral oil in them and it is usually recomended. if a piston engine uses mineral oil (and they are not supposed to burn oil) then the only left over from combustion is carbon. now if the piston has ring failure then it will leak oil into the combustion chamber and be burned off. . . and amazingly your exhaust turns into an ugly blue color. that means that something else is burning off. mineral oils (and you said it yourself) contain many different additives. so what makes it burn so well? it doesnt. the combustion of the fuel and air end up burning the oil onto wherever it decides to go. so really you are not getting anywhere by saying that dino juice burns better than man-made juice. . . cause in the manufacturing of the synthetic oils they may have taken busted rings or even a rotary engine into consideration and made it relatively environment friendly. that last sentence is only theoretical so dont hold it against me. i just know that hot *** turbos need synthetic oil.

rotorbrain

gzon,

can i get that in the states? do you know?

Enthu

iTrader: (1)

Alot of peopel here use synthetics, including myself. I have never seen a post saying not to use because they experienced damage from it firsthand. use a sythetic. our turbos spin at very high RPM and a synthetic will give better lube/protection. I use Syntec 5w-50 ( I would like to find MObil 1 in this viscosity, but no one seems to have it) and a pure one MX-6 size filter. My FD has ran better on the syth oils than dino/mineral oils. go ahead and us a sythetic. if your worried about burning synth, disonnect the OMP and pre-mix, or get one of those OMP replacement pumps that has a 2 stroke oil resevior. Technology has come along way, and taken sinth oil with it. don't be afraid to embrace.

rotary-tt

Well after numerous threads on this topic during the last year, I decided to run Mobil 1 (changed it last weekend). Although I was against it at first, I've become convinced that Amsoil and Mobil 1 are ok based on the low ash content. Also, the Mobil 1 site said they've done extensive testing with the rotary with no adverse effects.

Since changing over, I've noticed the turbo's spool faster and the car runs somewhat cooler. Seems to run better also. I just wanted the extra protection since I drive less than 10 miles and\or run it hard.

Hopefully I won't be buying a new motor soon due to the change...

FD3S LIGHTNING

You must have good self-control to only drive it 150mi./ 4 mo..

jmseven

Kendall has 10w-50. I used to use it on my T2. I had also used Redline 20w-50 in the past when racing.

I have used full syn in the past, Redline 20w-50. I really liked it, except for the overall cost. My engine seemed to like it alot..including my turbo. I did notice a difference in acceleration. I had had it dyno'd and did notice a increase in HP's. Just about 1% increase.

sheaa

Regarding Mobil 1, what grade is recommended in hot weather? Stick with 10W-30, or their performance driving formula 15W-30?

juliof

The FD is my weekend ride so I dont drive it that much, but I do replace the oil every 4 months so the motor has only seen fresh oil since I bought the car.Again if you replace youre oil every 3K or less synthetic dosent make sense.There is no proof 13BREW will last any longer running synthetic over mineral based oils or else everyone would have switched by now. Better chance of a motor rebuild from o-ring failer than type of oil.

neo_omega

Let me add something to the fire. I saw all the Japanese rotary oil are 15W-50 Full Synthetic . So I'm using Mobil 1 15W-50 Full Syn now.

san7

So maybe there is no evidence for synth oil making a rotary last longer. But wouldn't lower oil operating temperatures and better lubrication, comblined with word of mouth from everyone on this forum that runs synth and the fact that synth is good for turbo's be enough to convince you? It did for me, and my car does run better. I switched mainly for turbo longevity, but I found that the engine is smoother. Redline also says there oil leaves no deposits when burned, and my car has alot less blue smoke at startup. .02

rotorbrain

this is all very good info. finally, we have extremely good info on what oils to run. everybody creates a good argument. i have been running synthetic for a while and will stick with it (although i have been running 20-50w, ill probably go with 10w-30 this weekend). i did not know that mobil 1 tested their oil on rotaries .. . i wonder if castrol tested theirs. it is cheaper than mobil 1 and im a castrol fanatic, hehe. keep all the good info coming. personally i think somebody needs to make this sight more visible so others can see it for there oil info. . . ahem, ahem. hehe

neevosh

Has anyone developed any oil leaks after switching to synthetic? I would like to switch but am worried it might cause oil leaks. Also, I've heard from a few engine builders that after tearing down an engine that used synthetic for a rebuild, the housings looked almost brand new. Hardly any wear on them.

juliof

A more effective means of lower temps would be a upgraded cooling system with bigger oil coolers , both of these will lower temps much better than just running synthetic oil alone .I am not saying that synthetics arent better than mineral based oils, they are but in this application the FD 3rd gen which rarely makes it to 100K without a new motor, you can run systhetic oil all you want and still have a o-ring failer,over heating, detonation as the most likely reason for engine rebuild type of oil is the least of many problems.

crai6m4ck

Don't use synthetic in a rotary! Rotary engines inject oil into the combustion chamber (just like If you were to remove your oil metering pump then you would have to add oil to the gas) and synthetic oil does not burn the same way that mineral oil does.

PraxRX7

I have always run 10W40 Castrol GTX...

No problem, Change it every month (or 1800 kms)(1200 miles)...

Although the 2nd and 3rd gen could be semi-different...

san7

juliof. I am not saying that synthetic oil is a substitute for upgrades! Did I ever say that, nope. Would I ever say that, I do not think so. I run synthetic mainly for the turbo's. But don't even take my word for it. Just try it. It does make a difference in smoothing out the engine.
Just so you know I have a fluidyne, AST, & DP. The primary reason for these mods were to aid in cooling and reliability. A second oil cooler is in the works. I just thought we were talking about oil in this post, not cooling mods.

neo_omega

Who knows the rotary engine better than those Japanese RX-7 tuning shop? Just go read those R-magic and FEED ad in the RX-7 maganize, you will see they make some special oil for our car. And you will see all those oil are Full Syn 15W-50.

A lot of people are using full syn oil. A lot of them have not problem at all. Some cars here with very high mileages are using Full syn oil. So the fact is full syn oil will not kill your engine and won't make it less reliable.

gzon

sorry, no idea.

racer rx

Hey Guys...
I just picked up some Mobil 1... 15w50.

Will I loose a little HP with that thick of synthetic?

I know I can feel the difference between 10/30 and
10/40. The 10/30 has a little more zip when you hammer on the gas.

What will I notice with the Mobil1 15w50?

thanks jc.