So currently I have a 87 tune from Tillman Speed loaded but I want to move up to the 93. I used the 87 tune this week for the gas that was left in the tank, I just filled up with 93 with the onboard computer listing about 39 miles to empty before hand. Do you guys think I'm good to go or do I still risk pinging and detination?

 

you will be fine imo

 

You're good to go. The PCM can adjust to that very minor (if any) octane difference.

 

You're OK, flash away...

I think people are too concerned about running their tanks of lower octane fuel to the absolute minimum before flashing to a higher octane tune.

 

You should be good to go but if you want to be extra careful just wait till you run it down to about a half tank, fill it up and then flash it.

 

I was bored one day so I romped around town and got down to 4 miles to empty :P

 

I've had it say 0 miles to empty. It's not good to do that, and I'll never do it again.

 

How big of a performance gain will you get going from an 87 to a 93 tune...

And using the right gas..