BA1125

I have a 2012 FX4 with the 18" wheels and tires. I'm getting a set of FX4 20" wheels and 305/55/20 Mickey Thompson ATZ tires, can the dealership reprogram my truck/speedodometer to accept the 20" wheels and taller tires?

Thanks,
Brad

jonbar87

I called and they said they can go up to like 33's but supposedly "their tool can't program anything bigger than 33's" but I know every dealer is different so I'd just call them and ask....

swazispencer

Thankfully for the Raptors 315/70/17 tires, the dealership can program up to 35s.

BA1125

Sweet... The 305/55/20 is a 33 so I should be fine then.

blyons808

I upgraded from the stock 17" rim with 235/75717 (almost 32") to 18" rims with 33" tires and my speedometer is spot on now. From what others have experienced on here, the 33" actually makes the speedometer more accurate. Supposedly, the stock speedometer is a little off from the get go. I'm not saying that all the trucks are this way, but this is what I have experienced personally. I have a bunch of those radar things the cops put out that show u ur speed as u drive up to it. So far, all of those radars have been spot on with my speedometer. I suggest u try and drive past one of them if u have one in ur area.

BA1125

Will do.

I have noticed it seems like its off a 1-2mph right now

newsshooter9

In my book 1-2 mph could be the difference between running and hiding from police and going about my day.