It's labeled as racing fuel at a gas station about 15-20 miles from my house.

It's only about .15 more than premium (93 octane).

I saw the thread about touluene (sp), and I was wondering what you guys would think about running 99.

 

Theres a gas station about a mile away from me that has 100 octane.. but they are selling it at about $3.99.. WTF!

 

Since you aren't going to higher compression pistons as well I doubt you'll see a difference. Racing gas here is 105octane (I think) and sells for about $5 a gallon so 15 more cents for 99 octane is pretty cheap.

 

make sure its quality fuel, cause, yes, thats very inexpensive "racing fuel"

SCC did a test on the Z very soon after it came out and they compared 91 to 100, and got I think 2 or 3 hp. not much, but people have paid 250 for an intake that is questionably generating that much hp, so cant say its all bad. if you were to get an ECU itd be even better too.

dont go too much higher, theres racing fuel at 110 and higher octane, this will not burn cleanly in our engines, and will thus fry your cat, but 99 is fine.

 

higher octane fuels aren't that big of a benefit for stock N/A cars.

Slam a twin turbo and boost controller in that Z and you best run race fuel if you plan on pushing 1.5+ bar through it on a regular basis. (esp. in hot weather like out here in AZ)