OK Wandell or Nebraska....
Got a good one for you.
07 Screw running 35's (same set up as you Nebraska) and I need to fix my speedometer. Local dealer is scratching their heads because apparently it was easier on the 04-06 trucks... Something about the PCM has changed...

Does anyone have any idea? I have a buddy who works for an ABS supplier.
He has a computer that can rewrite code but he's not sure because the Rotations per mile for tire size is referenced in several locations for the Braking systems (for Traction control and such).....

Nebraska Let me know if you were able to fix it.

Thanks!!!

 

I got a hypertech power programmer, it redoes the speedo and gives more hp and torque. Plus it stiffens the shift points for better performance with bigger tires.

 

I'd try another dealer or start saving for an Edge or Superchips tuner.

 

I'd get an Edge or learn to deal with it. It shouldn't be off by more than 5 mph if that.

 

What Wandell said .

 

I measured the old fashion way by driving along side my wife... its actually closer to 7-8mph off...

 

I have an SCT xcalibrator 2 for my Mustang but it's locked to my Mustang Vin and I don't want to erase the programs that I have....
I'll try another dealer...

 

i recommend a diablosport predator. lots of options on that including tire size and you can actually put in rotations per mile!!
i done a gear change on my truck and when i was doing the gear change on the programer, i figured in rotations per mile, and installed it on the program. pretty darn accurate not more than 1-2 mph off according to a couple of those police radar things that tell you how fast you are goin.

 

Another option if you do not want to have a full tuner, is the Superchips Tirepaq. It does the tires and shift points.

 

Sorry it took so long, but I agree with the others about the tuner. I am currently saving for a tuner. I have a local shop that will do a tuner, custom tunes, and a dino run for $500. Hopefuly it will be my anniversary gift from the wife!!

Nebraska

 

That would be a nice gift... My wife refuses to buy me stuff for my truck or mustang...

Nebraska...What do you think of the truck? I'm happy with how it turned out....Did you fix your Speedometer yet? Assuming you got the 3:73's as well, our trucks probably are off the same amount...

 

Definitly try another dealer. There are plenty of dealer swapping larger tire packages as add ons. Also try a performance or off-road shop.

 

I think it turned out GREAT!!! I like your wheels. I have not gotten my speedo done yet. It will be done when I get the tuner.

Nebraska

 

jus get a programmer i have superchips and that fixed it and that programmed my speedo