Octane Ratings at elevation

[Snowfish00]

I have been reading about the PHP programmer and am thinking about getting one for my 04 F150 w/ 5.4l engine. I live in CO and our regular grade gas is 85 octane and our super premium is 91 Octane. I believe they oxygenate our gas and that is suppose to help offset the lower Octane levels at this elevation. Do you recommend running the higher octane gas or are there programs that will work with our lower octane fuel?

I just got this truck at the beginning of the year and I have tried both regular and super premium and have not seen a major difference in my mpg (about .5 in mpg) on 3 tanks of each grade. I was wondering what kind of difference a programmer would make with my mpg. I try to keep the rpm's below 2k and try to avoid rapid acceleration or decelerations. Though when I am on the highway the posted speed limit is 75 and that takes me over 2k rpm.

Thanks for any input!
Adam