anyone used octane booster and whats is the feed back?

 

It's a waste of money on a un-modifed RX-8. Octane doesn't provide power, tuning & upgrades do. Octane only allows you to get the most from CERTAIN upgrades like FI or ECU changes.

 

Don't waste your money. Unless your pinging run 87 octane, the RX-8 runs better with the lower Octane.

 

I've used them before--any effect I felt was probably placebo

 

you mean higher octane right? every rx8 is different in how it runs on certain octane. ived used 87,89,91 and 93. i def noticed a difference when i ran 87 on difference occassions. i can feel the difference when running with 91 or 93, nice and smooth. the 87 felt a little jerky. the 89 i can't comment on because i only ran it once and it was awhile ago.

 

No, i think he means LOWER octane.

The effect is well documented that most rotaries run quite well on fuel that is low on the octane scale.

Go figure.

S

 

erm well anyone know what is the octane level of shell regular petrol?

shell regular better or shell super better?

 

How come the manual says use Premium fuel?

 

We shouldn't be thread jacking, but he definately means lower octane. Octane = resistance of combustion. So the higher it is, the harder it is to ignite. Useful when you're in a turbo car with high compression, not as useful in the NA rx-8. Fuel varies from state to state, and by brand, some people get good results with 87, others not so good. Try it out and see if your car complains.

 

All of this is moot, anyway.
Over-the-counter octane additives only increase AKI by .1. That is right 1/10 of a point.
Throw a can of "Boost" or whatever in there and you take you mediocre tank of 89 all the way up to a roaring, snarling, hi-potency trough of 89.1 AKI.

If you want a real boost in octane (which will probably do nothing for you unless, as noted above, you are pinging with your current AKI), throw a gallon of Xylene in there (Xylol/Xylene is a paint thinner - you can get it at Home Depot for about $14 a gallon).
One gallon of xylene in a full tank of 89 octane yeilds 91.
If you are feeling particularly frisky, use 93 octane to start and your AKI jumps to almost 95 with xylene.
Xylene has a native AKI of 117.