I'm getting ready to put 285/70R17's on my 03 Supercrew 4x4. Do I have to go to the dealer to get my Speedometer recalibrated or is it something a guy with limited automotive knowledge can handle himself?

 

I've called three dealers locally about this same issue..the only one who was willing to do it said he was limited to the biggest tire size that ford would put on a stock truck..he couldn't do it for my 315's but it should be no problem for 285's..

 

It should only be one or two mph difference

 

Programmers can correct this as well .. I'm looking into one for mine to correct the speedometer/odometer and the added performance gains.

 

I put the same size on my '02 flareside 4x4. Costco had a computer program that told me what the difference would be. Only 2mph at 65. Not a huge difference to live with.