you ll love the predator turner you can do so much ! I would have never got my truck if I couldnt use a tuner ! we only have 91 oct here but it runs so much better and even better as the milage goes up ! I went 91 oct for a few mouths then turned off mds and went to check my a.c. fan seem it never came on in 100 temp well it was set to turn on at 235 degrees that was why ! I run 204 on most hot days here ! allso I have the big horn set up and checked tier size it was way off set it to 20 inch 275s now it shifs alot better now ! I allso changed my axel to 4.10 s or biger lost 1 mpg is all I could see so much better the that little grears that were in it. I allso found a great speed shop to set my tuner up didnt have 91 oct on it found it on there list where I got the tuner from so all in all you ll love it fun to use and frist time for me it was pretty easy to do ! good luck and have fun !!!!