ApeXX

EDIT: Sorry title should be speedo, can't type this morning!

I'm looking to replace my stock wheels (15) with a set of larger diameter wheels, mostly likely 16-17 inches. From what I understand speedometer/odometer readings are based off of pre-set factory tire circumference, which is multiplied by axle turns to compute those speed and distance readings.

The problem is that when I install the larger tires, my speedo/odometer readings will be off significantly, most people I've talked to say anywhere from 5-15MPH.

Once the tires are installed, can I take it to a Ford dealer or my mechanic and have them flash the computer or what ever process it takes to recompute tire size? If not, how else do I solve this problem?

Thanks!

socalwrench

Yes, you need to have the computer adjusted for the taller tires. You're Ford dealer can do this- it takes about 5 minutes with an IDS.

ApeXX

Thanks, I appreciate the info!

domindart

Oh, Ill have to do this too. thanks guys.

socalwrench

I'm not sure your FOX requires a reflash. If you're speedometer has a cable going to the transmission- than you need to change out the little plastic gear to adjust the speed reading.

The reason I'm not sure is if the tire size can be changed. If you have ABS- then I may look into. Otherwise- just swap out the gear.