I have the Hypertech tuner programmed to my 2002 F-150 4.6L Supercrew and I have been using the 87 octane program. If I go to the 91 octane program will my truck increase performance and mileage? Has anyone actually done any tests on this? Are there any rule of thumbs when it comes to octane and mileage? Will the cost of 91 octane be justified with more mileage?

 

I usually find the $3 difference at the pump yields about 1 mpg increase. With your vehicle and driving style, the only way to find out is to try it.

 

do not waist the mony will not make a bigg differents