IvanRad

Also will i benefit from tuning my car to 91? and should the gas tank be empty before upload the new tune?

Boneman

The benefit is very apparant once you've fueled up and flashed over. As far as empty... get it close. I've filled from 1/4 tank and flashed and have been OK. Usually though, I wait 'til the car starts nagging me about "LOW FUEL!"... then fill it up.

Shelby350Mike

I would run a tank of 91 in your car, fill the tank up again, then download the new tune. Much safer to make sure everything works out ok.

Also, I've only had experience with Bama tunes, but from that experience, I would only ever go with them when it comes to tuning. Great customer service and the tune is legitimately perfect.

IvanRad

okay . so 91 apparently gets better gas mileage if you hand calculate it.