Rotaries Run Hot?
Originally Posted by valpac
I have never used synthetic in either my old RX-7 or Rx-8. Maybe the fact that he's racing it has some bearing as to why he uses synth. I've never had problems using reg. oil. (probable because I change it so often) I see no real value added in synths. IMO. Any good SL grade oil works for me.
Frequency of oil changes is more important than type of oil used. Change it as often as you can afford, EVERY 3000 miles, religiously. Or less.
Frequency of oil changes is more important than type of oil used. Change it as often as you can afford, EVERY 3000 miles, religiously. Or less.

I'll stick with the semi-synthetic then, the one Mazda-Europe recommends, and change it every 3k miles...
All of my previous RX-7s have run at 82-88 celsius standard operating temperature. Its not that the rotary runs hotter, its that it generates more heat than a comparable size piston engine, and the oil differences.
Originally Posted by wakeech
doesn't sound right to me: water cools better than oil, and can take higher tempuratures...
Originally Posted by wakeech
...dirt contamination isn't such a deal as it used to be with the molecules suspended so don't everyone start freaking out and changing at intervals smaller than the manufacturer's recommended (which are already as close as they think the maintence service market will bear).
Changing my oil every 3000 miles is not freaking out. My engine will just last longer.
Originally Posted by valpac
I have never used synthetic in either my old RX-7 or Rx-8. I see no real value added in synths. IMO. Any good SL grade oil works for me.
He said though I should wait until after break-in (8-10K miles) to change to synthetic.
I am still going to do some more research before I change over, but I'm leaning towards synthetics now.
Mmmmm... Rotary Donut
Joined: Nov 2003
Posts: 2,376
Likes: 4
From: Lake in the Hills, IL (NW Chicago Burbs)
Originally Posted by DrRockin99
What is a canscan?
Originally Posted by valpac
Well, I may have to re-think this position. Today I had my oil change and asked the service mgr about synth and whether it would be worth it or not. What he said was either works fine BUT synth sticks better to metal than standard oils and provides better start-up lubrication...
I'll try searching myself too, but can't wait to hear what you'll come out with...
Originally Posted by valpac
no, oil has a much higher boiling temp than water and can therefore hold more heat.
Last edited by wakeech; Dec 5, 2004 at 10:46 PM.
Originally Posted by valpac
Frequency of oil changes is more important than type of oil used. Change it as often as you can afford, EVERY 3000 miles, religiously. Or less. 

Every time that I've checked the oil, the oil looks brand new. Anyone know if the oil in the rx-8 does anything other than be injected into the engine once in a while? If the oil is simply being injected and thus burned, then the oil that is sitting in the car really doesn't get dirty.
Good oil and frequent changes of oil & oil filter will help the 8 run cooler. I live in Southern Cal and have been running Royal Purple 5w30 in the engine for quite awhile and use only K&N oil filters and change my oil every 5,000 miles, in addition, I run Royal Purple in the the trans & diff.
My 8 is highly modified and I enjoy driving it spiritly but, not trashing it. After extensive research, I went with Royal Purple and have been very happy with it's performance.
My 8 runs cooler(the shut off fan never comes on)-the heat in the cab and under the car is not hot, no matter how fast I drive it. The key to using a good quality synthetic(Royal Purple, Redline or Idemtisu) is changing the oil & filter every 5,000 miles(since synthetics WILL contaminate like dinos).
Common sense will dictate to do some research at the Oil Institute website to learn how oil works both dinos & synthetics & how they can apply to work in a rotoray engine.
I sleep well at night knowing my car is getting the best care I can give it and it rewards me with good performance,reliablity and no problems.
My 8 is highly modified and I enjoy driving it spiritly but, not trashing it. After extensive research, I went with Royal Purple and have been very happy with it's performance.
My 8 runs cooler(the shut off fan never comes on)-the heat in the cab and under the car is not hot, no matter how fast I drive it. The key to using a good quality synthetic(Royal Purple, Redline or Idemtisu) is changing the oil & filter every 5,000 miles(since synthetics WILL contaminate like dinos).
Common sense will dictate to do some research at the Oil Institute website to learn how oil works both dinos & synthetics & how they can apply to work in a rotoray engine.
I sleep well at night knowing my car is getting the best care I can give it and it rewards me with good performance,reliablity and no problems.
Originally Posted by valpac
change to synthetic.
The reason I used non-synthetic in my old RX-7s was because they were turbo and thus broke down the oils a lot faster, so you have to change the oil more frequently, so why spend way more money on Synthetic when non-synthetic will last just as long?
Originally Posted by salituro64
I keep reading about that rotary engines run hot. Does anyone know what the normal operating temparature for an RX8? Unfortunately you can't tell by the tmeperature gauge that has no numbers. 

Could this be a reference to the cooling issues inherent to the engine type, having more to do with the effective displacement vs. combunstion chamer surface area ratio?
Essentially, in comparison to an otto cycle (piston) engine, a wankel generates more "waste" heat per unit area of the combustion chambers, which makes cooling them a more difficult task than is the case for pistons. (one of the wankel engine reference sites had a little more discussion of this, but I can't remember which one at the moment)
Originally Posted by JasonHamilton
... Anyone know if the oil in the rx-8 does anything other than be injected into the engine once in a while?
Thread
Thread Starter
Forum
Replies
Last Post
9krpmrx8
Series I Trouble Shooting
23
Nov 5, 2015 11:45 PM
RayBarron
New Member Forum
4
Oct 19, 2015 08:08 PM
dbarber
Series I Trouble Shooting
14
Jul 25, 2015 01:34 PM




