Are you saying that the people that have a flash tuner, don't know what they are doing are using?

 

How many people that make tunes for the 7.3 are using a programmer? I can think of 2, one of which only does it if you already have the tuner. Now how many tune on the TS or DP chips? I can think of 10, kinda goes to show you what is the best for the 7.3

 

aside from the chip/tunes debate i think your question is pretty much answered
also look at getting smaller tires with bigger rims the smaller the sidewall of the tire the less resistance to the road tires are a great concern when looking intor you MPG
hope this helps

 

I am currently getting about 13-14 on the highway as well. I have 315s though. It might just be what it is. The part that puzzles me is I have a buddy getting about 18 on the highway and he has 35s and a lift as well

 

How is he "getting" his 18mpg...

Lots of guys go by the lie-o-meter in the overhead...

Or they simply do not know how to calculate mileage.

 

Flash tuners for a 7.3 have proven to be less desirable then a chip for YEARS Rustin, you do not understand that a chip can over ride EVERYTHING in the PCM, completely replacing the existing programs.

There is NO down side to a chip. Period.

There are MANY downsides to a Programer.

 

Hand calculated. Miles driven divided by gallons to fill

 

Is his speedo recalibrated? What cab configuration?

Your MPG issue I believe is the lack of distance, your truck never warms up.

How ever 18 mpg is a bit higher then I would expect, unless its a single cab or he has a rather long commute.

 

I dont think its recalibrated, mine is either. I usually add a few miles on to even it out, or close to it. I have a guy thats coming through who is gonna put an ae on it for me this weekend. Should I have him make my speedo dead on? I know from the factory they are off, when I had the 285s it was dead on. My buddy has been at Ford 10 years he said the 285s make it perfect. My buddy has an ext cab lb like me. I think he said his last tank was an average of 16.5, and I think he is around 18 on the highway Im guessing. My numbers might be off, Im just going off what I remember

 

Mine is dead on with AE for the 37's...