Dan, I plan on chipping my truck but I have one question. When you say the chips need "premium" fuel, does that mean it has to be 92 octane? Or will the 89 octane suffice?

I have a 2001 F250 auto V8 4x4 with 35" tires, and a flowmaster muffler with a K&N filter. Thanks.

 

Some will run fine on 89, they just don't produce the extra horsepower that 92+ does. The added hp comes from premium fuel. If there were hp to be had on regular fuel, the factories would have tuned the truck for the extra free hp. The truck may ping and rattle on regular fuel after adding a chip.
Thanks
Danny