66and06stangs

This may be a sillly question but I still have to ask. I'm using the street tune on my SCT3 tuner that I bought from AM with Bama tunes. If I wanted to try the performance tune, which uses higher octane fuel, how low do I need to go in the fuel tank before I put the higher octane in it? Woult 1/4 or 1/8 of a tank be good enough or should I try to completely drain the tank (which is obviously more difficult to time a gas station stop)?
What have other done?

iMuf

I just had my car tuned and I think I was at about an 1/8 of a tank when I filled up

AzPete

I run mine until the low fuel light comes on.....then I have 50 miles to fill it with the new stuff.

AMAlexLazarus

Good question! I will personally try to time/guess when I'm going to be hovering over the E light-You don't need to be completely in the red to have it fulled up and you could even top it off with the higher octane once you're ready. Once you're filled up whip out your tuner, load up the performance or race tune and enjoy!

Let me know if you have any other questions, I'm always here to help out!

-Alex

66and06stangs

Thank you all. I was worried I'd have drain my tank or something drastic like that. This'll be easy!

AMAlexLazarus

Just like going to the dentist! Let me know if there's anything else I can help out with.

Alex

Nuke

Even though your PCM doesn't have the range of adjustability like some other cars, it should be able to make enough adjustment for minor octane differences to prevent detonation. Of course, if you are going to run a 91 octane tune for example, you can top of a 1/4 tank of 87 octane with 93 octane.

JJHoover

you can also put some racing fuel in it 100 or 116 octane

66and06stangs

I'm going to run it down very soon and try the next up tune. Still having a few issues just getting the car running good (vaccum leak in the crappy BBK CAI apparently, which I still am working). Thanks to all!

AMAlexLazarus

I would love to hear how it went, so let us know! The CAI's can definitely be a little finicky in my opinion. These cars are just too smart for their own good! Double-check your connections and let me know if there's anything I can help out with!

Alex