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

[Power Hungry]

Adam,

Just to let you know, the bulk of the tuning I had originally done on the F150 was at about 4200-4500 feet using 85 octane, so I am quite familiar with what these trucks will do under those conditions.

We've had a few people that have indicated they didn't notice any increase in fuel economy running our programming. Sometimes that's just how it works out. In most cases though we see about 1 to 1.5 MPG. Gains at altitude are usually quite reasonable because of the fact that we can go a little more aggressive on the timing curves, even with lower octane fuels. One thing to keep in mind is that 85 octane at 4000 feet is roughly like 87 octane at sea-level.

Most of our customers don't notice enough difference in performance or mileage (for daily driving situations) between low and high octane programs to justify the expense of the high octane fuels. Of course, the heavy to full throttle power is better on the high octane programs but the reality is that most people don't drive that aggressively and would rather save the money on fuel. Even those who are aggressive have noted that the low octane performance programs are usually more than adequate for their needs.

Hope this helps.