I talk to my dealer, he said this." in the new FORD computer we can not just enter any size we want. We can only enter stock FORD sizes." So in your case find out what sizes are available and have them program the one closest to your size. Look to Raptor wheels and tires I will bet you can find one thats close. Raptors have a size 33/12.50/18 which is only .2 difference from yours... Just a guess....

 

Wow, that tire is only 1.1" taller... any 33" tire size would work... sounds like you need to go back and raise hell.

 

Raptor tires are 315/70-17's. 34.6" tire. ;-)

And the Raptor and F-150 have different software or options available in the computer. They can't program sizes that don't come standard on an F-150. They can't program for the Raptor tires. Unfortunately.

 

Yea that's true... I just put on some 34.1" tires and the dealer told me they could re-program. Well it turns out that for 2010 and 2011 only stock tire sizes can be used from the ecm. the size that was on there was the 275/55R20 a 31.9" tire. After driving the truck with the GPS in it i come to find out the speedo is only off 1.5% which is very small, reads 120km/h when it's actually doing 122km/h.

 

Well the Raptor at my dealer had 33/12.50/18.... BFG AT

 

Well the tires are the stock tires for a 2010 F250.

I will go back and ask.

 

Bump for answer from a Ford tech!

 

Took my 2011 to dealer for reprogramming for 33's which they said no problem. Called me later and said they could get close near 1%. Drove home and determined I was 8% off so got my money refunded. Don't waste your time if you have 33's.

 

Ford calibrated mine to available stock tire size in the PCM for my flash. The flash in your truck is not the same as a Raptor, so seriously doubt raptor wheels will be available. They changed mine from 265x55R20's to 285x65R18 (which was the biggest available) - '09 FX4

 

if you want to adjust your speedometer, dont get the edge evolution tuner, as it does not support speedometer calibration for 2010+ (according to their website that is)