wakeech

that is so sweet

RotorManiac

Thanks for the answer.
I'll stick with the semi-synthetic then, the one Mazda-Europe recommends, and change it every 3k miles...

Icemastr

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.

valpac

iTrader: (2)

no, oil has a much higher boiling temp than water and can therefore hold more heat.

It was not my intention to cause a panic about changing oil frequency. However, the manual states interval of oil change for Schedule 1 is 7500 miles while Schedule 2 is every 5000 miles. (OM, Pgs. 8-4, 8-6) Both schedules are too long for an engine so oil dependant as the rotary. Only the Puerto Rico schedule says every 3000 miles.

Changing my oil every 3000 miles is not freaking out. My engine will just last longer.

valpac

iTrader: (2)

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.

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.

DrRockin99

What is a canscan?

G8rboy

A diagnostic tool that plugs into your OBDII port and a laptop or palm pilot to retrieve trouble codes, CEL's, and real-time data. CAN is the newest (fast) protocol used by the mfrs for new cars to interface with the vehicles' computers.

RotorManiac

Hmm, I remember some poeple here saying to stay away from synthetics, that's why I'm wondering which oil is the best...
I'll try searching myself too, but can't wait to hear what you'll come out with...

wakeech

sure, but that tells you nothing without knowing the molar heat capacity of the matter. water needs a whole lot more energy to raise its tempurature per mol/litre/pound, it's better for cooling. And besides that in an engine water has little else to do other than cool whereas oil can be denatured and damaged providing cooling, ruining its ability to provide lubrication in the engine.

mysql101

I've changed my oil on my rx8 every 3000 miles - I actually did the first oil change when the car had 1500 miles on it.

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.

Mike Z

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.

valpac

iTrader: (2)

You know, I had the very same debate when I owned an RX-7. And I used standard Valvoline the entire time with no troubles whatsoever. I dont know why I am going against my own instinct. Didn't use it then, not going to use it now.

Icemastr

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?

bgreene

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)

valpac

iTrader: (2)

The oil is sprayed into the rotor cavities for cooling.The oil gets very hot and cooks a bit. So the oil will get "dirty" by this process.