...for 93 octane will putting in 94 octane mess up performance? I put down 93 octane for the flash because I'm in the military and of course uncle Sam likes to move us and knowing that not every state doesn't have 94, I was just thinking ahead, (please Uncle Sam don't send me to cali).

And since we are on the topic of ocatne will running 108 leaded hurt the car when I head out to the track? What mixture should I do? half and half, 5 to 1? Any suggestion are appreciated I don't get to the track very often since I'm a shift worker working 6 on 2 off.

 

Using higher octane than is required is not harmful.

Regarding the use of leaded fuel, only use it if you are not running a cat!

 

This is correct - slightly higher octane will only allow more detonation resisitant tuning and allow the ecu to run better ign timing

Go for the 94 !

 

94 it is! I'm running the AMS high flow cat so 108 leaded is a no go .

thanks for the info

 

Yea. Leaded gas will make quick work of your cat.

When I go to the track, they have unleaded 100 for sale there.
Look around at the tracks you go to.
Most have a "gas station" somewhere on the property.

 

Are you putting half 93 or 94 and half 100 or are you filling the whole tank up with 100 octane?

 

In CA, with our crappy 91 octane, it would be good insurance to mix 100 in to get approximately 93-94 octane since you're going to be driving the car hard.

The 93/94 octane will also help prevent the ECU from pulling timing.

The reason someone might fill up with 100 is if they are running much higher than normal boost levels (to try and minimize detonation).

Otherwise, using more than 93 or 94 octane with a stock or mildly modified car is a waste of $$$.

 

I try to show up at the track sucking fumes, and then buy 3-4 gals of 100 to race with.
Remember, gas weighs about 8lbs/gal. Excess weight = slower times.
To fill up the tank would add over 100lbs.

Running that high of octane doesn't hurt anything IFAIK.
Once you have a high enough octane to stop detonation, the rest is a waste I suppose.
Remember, higher octane fuel is harder to ignite (that's why less detonation) so grab some
fresh spark plugs, or at least clean yours up.

Anyway, after I'm done on the way home I fill with 94.