I was wondering if 10W-30 or 20W-50 is ok to run in the NA RX-8.

 

10W-30 will work, but it's a little on the heavy side. I wouldn't try 20W-50.

 

Of course they will work.I am using 10W40 GTX.You will find your engine starts better,runs quieter and a little cooler.

 

As a side note, 20w-50 has been a standard for years for boosted rotary engines. Haven't seen much talk of using it here on 8club for the ones running FI, but I always used it in my 7s.

 

The bearing tolerances on the Renesis are tighter. There is less physical room for oil inside the bearing races. That's why you don't run as thick of an oil in this engine. All of the oil passages are also smaller than in previous rotaries. Keep this in mind if you want to run 20W50. 5W30 is perfect.

 

and the Rotary God speaks!!

 

This is actually not quite true,in fact the main bearing and rotor bearing clearances are tighter on 86-88 13B engines than they are on the Renesis.The oil pump clearances are essentially the same on both engines.

The MOP design is basically the same(other than the method of control)The oil injectors are basically the same.

The only significant difference in tolerances I could find was the rotor to housing side clearance,which is less on the Renesis engine.This has bugger all to do with lubricant viscosity.

I am not sure which internal oil passages you refer to but the top oil gallery uses the same dowels and O rings.(or at least it did when I rebuilt my Renesis).

Finally,when I got around to checking out my 1988 RX-7 Work Shop Manual,the recommended lubricants for temperatures over 80F are 10W40,10W50,20W40 and 20W50.

As I have said elsewhere I have been using 10W40 and my motor is fine.When I rebuilt it I reused the apex seals because they were indistinguishable from new(other than the broken ones).

My motor is quiet,even in the 110F heat in Las Vegas,it starts instantly, I am getting 23mpg on the highway,and using about 1quart of oil about every 2500 mile or so.

For those who prefer to use 5W20,particularly in hot conditions,the engine rebuilders are going to love you when your warranty expires.

 

Anyone else use this engine oil and feedback? Thanks.

 

I use 5W20 Royal Purple. I also live in Houston where most of the time temperatures range from 80-100.

Using this oil is this hot temperature is going too cause me too need an engine rebuild quicker?? What's suggested then?

 

rp is a plus in your favor--but 5w/20 will not mantain factory recommended oil pressures (50.2 lbs at 3K at 212F) you need 5w/30 at least--to do that.
olddragger

 

I don't understand... Why does it say on the oil cap too use 5w-20 then? If 5w-30 is used too meet factory specs then why doesn't it come from the factory telling you too use 5w-30?

Or is the factory just wanting me too destroy my engine?

 

just taking a wild guess here that you didn't search

 

In the US car makers have to meet CAFE standards. They all recommend oil that's on the thinnest side of what's OK for their cars. Not too much of a real difference in mileage, but every drop helps with the regulation. Mazda recommends 5w30 everyplace except North America.

Going one grade higher would not hurt any car. The one thing against it, IMHO, is that it's a tradition going back many decades, predating modern oil technology. (Tom McCahill always recommended it. As well as single weight, non-detergent oils.) Unless you live in a very hot place, though, I'd be leery of upping the "5" part.

Ken

 

nope... but I didn't start a new thread over my newbness either... So it's a win/win...

Thanks Ken for giving me a quick in depth answer. It's been 60,000 miles with 5w20... I'm going too get a change this Monday too 5w30...

 

I wasn't referring to you, but I run 5W20 with premix and as far as I'm concerned this "the engine builders are going to love you" crap is just talking out your @ss BS, there's absolutely no validation for that claim

the same for outdated theories and ideas that have no relevance for today's technology

 

awesome, everybody has a different opinion on what the hell too use... The oil pressure idea doesn't make any sense... If they meant for the N orth American versions too be 5w20, then they probably adjusted the pressure for that wouldn't they?

At this point I'm just staying with 5 20 unless somebody can prove too me that it lowers the engine life

 

If it makes you feel better, they even use the 20 weight in Japan.....
Look at this video .. 4:50 into the video, they use 0w20....

http://www.youtube.com/watch?v=lYEpUWm-S0Q


5w20, 5w30..... either one should be fine....

 

exactly drive and enjoy the car and enjoy life. It takes all kinds for the world to go around and who really knows?
olddragger

 

And what do you think running premix is?An idea which has relevance for today's technology?Maybe you should take the bag off your head and see what is really going on around you.On second thought keep it on!

 

nice video...it teaches you things on dechoking which the user manual isn't really clear on.