I have a 1999 F-150 XLT 4X4 with the 5.4L engine, auto transmission and 3.55 axles. The truck came with the standard P235/70R16 tires. I want to install larger tires, say P255/70R16 or LT245/75R16, both of which are options. How do I recalibrate the speedometer/odometer etc? The dealer and local speedo shops are no help. Is the procedure in the Powertrain Control Manual so I could show the dealer how to change the calibration? Would it hurt to run the bigger tires without changing the calibration? Any help greatly appreciated.
Michael

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1999 F-150 XLT SC 4X4 5.4L
Black DZ Running Boards
Vent Shades

 

Pumpermike, Nothing to worry about as long as you going to the 255/70/16, When I picked up my truck from dealer in 97 I had all 4 235/70/16 on the truck,BUT the spare was 255/70/16 so I went back to the dealer the following week they changed all my 235 to 255 goodyear after my complaint. Also note from the Kelly tire dealer, 235 to 255 is no problem,just an option size from dealer. what they should do is put 255 on all F-150 as soon as they comes off the assembly line. I guess in my opinion just another way to make a fast buck.

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1997 XLT Supercab emerald green,4.6 auto superchip, rear dual exhaust, Atlas wheels w HP 275/60/17 tires, Lund steps and quarter window shades, Outland grille guard w KC daylighters, piaa 1000 in bumpers openings, Trenz billet grille, edlebrock ISA shocks, Powerslider, stainless steel fender trim, Delta toolbox, putco bars, fluidyne cooler, Airaid kit, Gentex electronic compass dimming mirror,Downey SST tonneau cover, Snugtop topgun is on the way, customize hood next.

 

Talked to another Ford Dealer and they can do the speedo recalibration, using the GEM II tester, for $49.99. I want to go to LT245/75R16 size tires. Anybody out there want five P235/70R16 tires for a good price?. Four have less than 2000 miles and the spare has never been used.

 

Pumpermike I went from 235-75-16 to 285-75-16 and that really changed my speedo. I took it to the dealer and he reprogramed the speedo and changed the gear in the tranny. Cost me $100.00 but cheaper then tickets. BOOM