ckrivin

Hello Listers
Have any of you tried to use Ethanol -85 in an RX-8? Anyone know what Mazda's position is on this? E-85 has more octaine than typical super unleaded, so may have some performance advantages, besides the obvious advantage of using less crude oil.
Thanks!
--Craig

LionZoo

E-85 also burns a lot hotter, so unless you like melting stuff I suggest you don't do it.

DaveCM203

You cannot simply run E-85. Cars that run it can recognize it. I would not advise puting it into your 8.

Here is a link you can check out if you want to see what cars will or will not use E-85. It also explains it alot.

http://www.e85fuel.com/index.php

ZoomZoomH

iTrader: (1)

IIRC E85-compatible cars have different fuel line designs that prevent rubber hoses from becoming weakened by the much higher concentration of Ethanol in E85 compared to regular gasoline.

actually I think E85 cars don't use ANY rubber hoses for their fuel lines

StealthTL

iTrader: (1)

If you just throw a tank full of E85 in, the mixture will get really lean, lean enough to stall all the time. If you get it running and drive it hard, you will soon be calling a tow truck, for much more serious problems.

Don't do it.....

S

Jax_RX8

Ethanol is also VERY corrosive! You engine/components must be designed to deal with this concentration of 85% - a rotary is not.

When it is blended into normal gas (mostly for octane boost, cleaning, and to reduce total gasoline consumption by federal law), it is blended in at no greater than 10% volume as normal gas storage tanks cannot take any more without corroding.

BTW - many "Top Tier Gas" compliant companies do use 8-10% Ethanol as one of the means to create their clean burning, reduced deposits, fuel.

http://www.toptiergas.com

rotarygod

What??? I don't think so.

E85 may be higher octane but that's not what determines it compatibility. Octane is merely a resistance to knock. It doesn't say anything about how fast it burns or how much energy in BTU is available from it compared to another fuel. There is less energy available from ethanol than from an equal amount of gasoline which means more of it must be used. The RX-8 ecu is not set up to run ethanol so don't try it. The engine could do it though if it were retuned. A small amount of ethanol in gasoline is fine and you probably have been running it the whole time. You really don't want more than about 10% or so unless you can retune your engine for it.

It isn't ethanol that is bad on rubber parts. It's methanol that is. The bad part of ethanol is that it is hygroscopic which means it mixes well with water. As a result it will actually pull moisture out of the air. Your gas tanks are vented which means there is always air in there. Water can cause things to rust as we all know but it also doesn't mix well with fuel. At least not with gasoline. Don't think you are getting free water injection out of it. It doesn't work that way.


Forget about running E85. Even if you had a car that could run it (and the RX-8 can't), you'll get less power and economy out of it. If you had a turbo you could get more power out of it before detonation but you would still really lower your economy so there is a tradeoff.

LionZoo

My claim of ethanol running hotter was learned from a melted heat gasket.

The Cornell FSAE team runs E85 for their car. Unfortunately for competition, the mix wasn't quite right and the team unknowningly used something closer to E97. The result was hard starting, though the car ran fine after it started until it melted its heat gasket.

zoom44

perhaps reading your OWNERS MANUAL would answer question about Mazda's position.

were the heads aluminum?

e85 is corrosive to aluminum.

and to reiterate- read my signature

LionZoo

Yes the heads were aluminum; it's a modified 600cc Suzuki bike motor. That might be the real reason and if so, my apologies for misinformation.

rotarygod

Fortunately there are no aluminum interior surfaces in a rotary. We have aluminum rotor housings but the surface of them is a steel sheet metal insert.

willhave8

I don't think the original poster has a manual because he doesn't have an 8 and was probably just doing some research

globi

E85 would definitely be fuel to go if one wanted to poduce a FI RX-8 with record performance (and not willing to purchase race fuel).

* higher octane rating
* higher latent heat -> more cooling
* more fuel needed -> more cooling

If E85 was significantly cheaper than gasoline, than nobody would care about the fact that fuel mileage would go down. (Gasoline just needs a tiny anti-terrorism tax).

Here's an interesting video about Ethanol:
http://video.google.com/videoplay?do...ech+talk&hl=en