I was on a dodge thread and read where an owner of an 04 2500 Hemi was able to pay his service dept approx $60 to re-program his computer to compensate for his switch to 315/70 BFG AT's. All he needed was the rpm at a certain mph. Is this possible for the 04 F150's. I would rather not mess with the tuner right now if I can just pay the service dept to correct it.

Thanks, Jerry

 

Yes the tire/wheel size is programmable. Not sure what the cost will be $70-$80 if I had to guess.

 

The only thing the stealer needs is Cash and the size of tire. I have heard that some stealers may not program the computer for tires larger than the largest stock tire they came with, that roll over thing? Or you could by a Performance Programer and do it your self, and raise the speed limiter, and get a few extra hp.

 

Thanks for the info. I would go the programmer route, but I'm planning on purchasing the ESP when I get home. I know I'm playing with fire by adding the spacer/tire combo but I really don't want to mess with the computer, just adjust the speedo/odometer.

Would you service techs happen to know if your dealership will install a daystar-style spacer lift and what the approx. cost would be? I know this varies across the board but just looking for a ball-park figure.

 

I just went back and forth with this but for some slightly different reasons. I think your odds are pretty good at Ford being able to get you dialed in. It just cost me about $80 and I gave them the information ranges for the possible options. In other words I mapped out just about every tire size with stats ordered small to large diam/circumference. Mapped these back to gear ratio possibilities. At first I didn't believe them that they only had a small range of calibration that they could do. The service tech was really helpful and I felt he did his best at getting my computer as accurate as he could.

It looked to me that he entered a selectable tire size and each showed stats including rotations per mile (I think this field was actualy what it used). Also entered a gear ratio number that the programmer spit back on combinations that were not offered options. This included a 4.10 ... I guess because it wasn't a possible option my SCrew. That left us with only the current 3.55's or a 3.73 to work with. So, then the hunt for the smallest tire ... that ended up being a highway tread 235/70/17 as its rotations per mile was less than an all season.

Through all of this I didn't get the largest tire limits he had to chose from but it sounded like there was more flexibility/options going to higher gearing vs lower such as I needed with my recent 4.56 gears.

No, we didn't get my truck calibrated ... got it to about 12% from 26% or more out'a wack.

 

I'm assuming that by staying with my current 3.73's and the only variable being my tire size, they should be able to dial it in. I won't be changing gears, just tires from 275/65/18 to 315/70/17. From what I've read on the tire charts, it's roughly a 3" difference. Eventually I do plan on going to 4.88's but that's after the warranty expires and the truck is paid for.

 

Correction to my last post ... that 235/70/17 tire; had more rotations per mile ... it was "less" in diameter.

 

Since you've 3.73's ... even if luck would have it that they somehow didn't have a 315/70/17 as a tire option ... you could use 3.55 gears and a 285/70/17 as a net equivalent.

 

Thanks 64 I'll definately keep that in mind, just in case.