Shell did have a Racing fuel available to the general public but phased it out awhile ago. The higher the octane rating, the more timing you can put into the engine when tuning. The only other benefit is its a cleaner burning fuel and acolder burning fuel. When it combusts, it explodes a bit harder so you might find the car revs a little quicker. Put some in your car and see if you notice any difference. It will not damage your cars motor.

100 octane fuel is usually 98 (or even less) with ethanol mixed in to raise the octane I believe.
Personally I wouldn't use it - my car did some weird sh1t when I was running ethanol in it...

i wouldn't put ethanol in my lawn mower! there is a reason they can only use so much of it in petrol, because if they use any more bad **** happens. its basically watering down fuel with cheap ****. if it was any good they wouldn't limit the amount in fuel.

if you want 100 octane pour some octane booster in your tank. but as said above you wont notice a huge difference unless you tune the car for that octane

14nce;173767 wrote:

Only issue with ethonol is it eats seals in your fuel systems abit fast

in my opinion thats a perfect reason to avoid it

"e85 is not suitable for use in any other motor vehicles other than those designed specifically for e85, such as the new SAAB BioPower 9-3 and SAAB BioPower 9-5."

thats quoted directly from the United website (only seller of this fuel in aus)

i know its not the 100 octane the OP is talking about, but its wat 14nce mentioned.

heres the link if anyone is interested:

http://www.unitedpetroleum.com.au/media.asp?pgID=203

I basically said that in my post. Your car has to be tuned for it, as it takes alot more fuel to get correct AFR's. jumping from 760cc injectors to 1050cc injector for the same AFRs should be a pretty good indication of this. If you car is not tuned for this fuel it will go bang as it will run lean.

But having your car tuned for this fuel is the cheapest gain in power you will ever get.

walts22;173784 wrote:

I wouldnt say its the cheapest power gain you will get when you consider upgrading injectors, fuel pump etc. plus the cost of the tune.

if you have plaaned on running E85 from the word go you would be purchasing apropriate injectors (price different between 760cc and 1050cc is about $70 for the 4), fuel pump (about $50 more) and the tune would be the same weather you are running 98 or E85, and most aftermarket ecus will run multiple maps so you can have both tuned at intial purchase ( at most $200 extra, when its only $650-800 to tune a aftermarket ecu from scratch)

so that $320 if you have planned it for a proven jump on an evo9 of 40kw. as the exhaust, turbo etc are also needed for the 98 tune at 250kw

doesnt matter what car its on, weather it be a v8, subaru or evo. at similar power levels and mods would see similar gains. the evo is just a car running e85 i am familar with

I used the 100 octane from United and i got worse economy and imo less power.

Wouldnt use it again.

Imo it is way under-tested, and the avaliability is average, and is difinately not worth changing a lot of things just to get it to run ok.

CRUISN;173845 wrote:

I used the 100 octane from United and i got worse economy and imo less power.

Wouldnt use it again.

99% sure ethanol is similar to LPG in that it has a higher octane rating, but needs to burn more fuel to do the same job...

Samon;173880 wrote:

Exactly. So a factory tune won't put in the extra fuel required for more power... now at E10 levels that's bugger all... but if you tried to run E85 on an engine which isn't tuned for it, it won't have enough fuel to burn properly and it will probably just stall.

and if it did run not long and you would have new light weight pistons