Archangel

I was wondering what would be the effects of using 110 octane in the 8. Either mixed w/ 93 or all 110. I have a 76 fuel station near me that sells it. Just curious before i go ahead and start adding it.

neit_jnf

After the ECU adjusts to the higher octane it advances timing and you should get more power.

Judge Ito dynoed his car with 93 and 103 octane and got 188 and 197 whp respectively, a 9 hp change with the 10 octane increase. 110 octane MAY give you a little more, maybe 15 whp compared to 91 octane.

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rudy8

15? what would the downside be of that, besides$??

neit_jnf

Extra speeding tickets? :D

I don't see a downside besides money, Judge Ito broke his car's transmission twice but it was on a extremely hard launch at the track.

JSE RX-8

higher octane fuel also costs more and the car uses it up quicker. those are the only downsides i see to higher octanes

wakeech

what sort of higher test fuel is it??

higher octane (again) DOES NOT relate to a higher calorific value, so unless your car is retarding ignition timing and even further over-richening the A/F mixture because of sensed detonation, this higher octane fuel will not help you at all...

...where the hell is that old fuel sticky that "someone" unstuck...

wakeech

read this for more info on boosting power with fuels, and what octane really means.

neit_jnf

I know more octane is not the same as more power but the RX-8 DOES dyno higher with higher octane. Judge Ito experienced timing advance when dynoing at 103 octane and it resulted in more power.

wakeech

...one data point does not a conclusion make.

takahashi

pure fuel is cleaner and smoother engine... you car may slide and you cannot hear anything from the renesis engine :D

pp13bnos

When I dyno'd my car at a recent RPNW gettogether, I made around 7 or 8 rwhp more than the next guy. I had about 1/4 of a tank, and added 4 gallons of 110. Downside was that the next day, I got a CEL. They pulled the code the next week and it was a P0420. Or a lean condition. They reflashed it, and its been go to go. CJ

dcfc3s

If you run a high-octane fuel, make sure it's unleaded. Leaded fuel will foul oxygen sensors and damage the cats over time.

Most high-octane fuel (above 100) is leaded, BTW.

But, if the car has no cats, and the oxygen sensors are heated, you can run leaded race gas . It's an expensive habit, though. The oxygen sensors will foul quicker than normal, but nowhere near as bad as an unheated (1-wire) sensor.

Dale

pp13bnos

I was running a 110 unleaded fuel. CJ

XDEEDUBBX

he said most

pp13bnos

Just wanted to clear it up.

Psylence

Sunoco 100 Octane can be found at the pump, just check www.racegas.com .

Sunoco also has a 114 Octane unleaded fuel. However, the nice lady at Sunoco informed me that due to the oxygenate levels in that fuel, it shouldn't be used with wideband o2 sensors. Even though its unleaded.

wakeech

...i'm just going to say again that running higher octane fuel will not get you any more power (as the calorific value of the fuels is pretty close to the same), unless you're having troubles with combustion (which would hurt your engine quite a bit).

considering that this is only a 10:1 compression motor, and the fact that wankel engines are exceptional at combusting low-"octane" fuel (hydrogen, for example), and that this motor is running atmospheric pressures, and further that the car is tuned quite rich on currect spec fuel maps, you're not going to get detonation unless you try to run propane.

Psylence

Common knowledge says that yeah, its a waste of money. $5 a gallon and all you really get is much nicer smelling exhaust.

Unless you have a heavily modified car.. my Subaru gets 5 gallons of 100 octane for every tank of 94. I wouldn't waste the $ on the '8 unless it was boosted or had some unearthly portwork done..

pp13bnos

Higher octance will make more power to a certain point. Here's a link with my results.

https://www.rx8club.com/showthread.p...highlight=dyno

CJ