I am planning on going to the track for the first timethis coming sunday. I want to put a 93 oct tune on the car. Right now I am using 87. Should I run the car until the tank is almost empty, tune it to 93 at the gas station, then put the 93 fuel in? I would run the car for about two or three days on 93before I run it at the track. Is it safe to switch it back to 87 after I am done with the track?

 

Just make sure you use octance higher than the tune in the car...not the other way.

 

what do you mean by that?

 

He means you always want to use gas with an octane rating equal to or higher than what your tune calls for. IMO your safest bet would be to run a tank of 93 through, then on your next 93 fill-up, change the tune...

 

so how long should i wait for until i fill the car up with 93? should i go until like the 50 miles till empty signal comes up? or should i go even further?

 

Well, this is up to you, really. You have to figure if you put 93 octane in the tank with 87 that was already in there, you're going to be a little diluted. If it were me doing the same thing, I'd put 93 in for the next tank and leave the tune at 87. Then when you fill up with 93 for a second time after that tank, change the tune to 93. This way you can be pretty sure that what you've got in there is 93 or damn close to it. After you're finished at the track, you can revert the tune to 87 whenever. If it were me, I'd revert it when I refilled the tank with the 87 (might as well enjoy the 93 tune while theres 93 gas in there ).

 

cool, thanks a lot... ill probably run the car for the next few days with 93... then see what its capable of!

 

And I guess you plan to run out most of the gas from the tank before you run it on the track, right? A full tank of gas weighs about 130 lbs (about 8 lbs per gallon).

 

Run at least a full tank of 93 before you tune it to 93. you don't want any 87 in there with the 93 tune.

 

well i never thought of running out the gas tank and then running it to decrease excess weight the fuel adds... the only problem is that i have to drive about an hour before i get to the track so im not sure if i can really run out the gas tank... i could always fill it up near the track with a little gas to run... but does it really make a difference on the track? like does it matter an extra 130 lbs? how much would it shave off the quarter mile times...?