I got a 91 economy tune(I have not tried the eco tune yet), a 91 performance tow and a 91 performance tow with 5th gear lock out, just in case I ever need it. I have been running the performance/tow and I love it. A little better milage and better driveability. It is my daily driver, I only tow about 8k 4 or 5 times a year. But I might have 1000 to 2500lbs in the back of the truck several times a year.

Shot

 

When you say 91, does that mean you have to run 91 octane?

 

Yep at least 91 octane. My truck runs better on the higher octane. better mileage too. They have other tunes for a lower octane, my truck just runs better on the good stuff.