Bigger Tires=computer upgrade?

[Bill Yocum]

I have a 98 Explorer XLT with sohc and will soon be adding a 4 inch lift, I have 235-75-15 tires and will be going to at least a 32-11.50x15, will my computer need to be reprogramed for this since most systems can only be good for about a 15% increase in tire size, I have a 3.55 rear end gear with the auto tranny, the only mod is a K&N drop in filter, I curently get 20.6 mpg on the hiway but I expect this to drop once the bigger tires are in place, thanks for any help.

 

[TEX]

You shouldn't have to have your computer reprogrammed, but your speedometer is going to be off. You might want to consider getting a computer chip due to the added power your going to need to push the bigger tires.
Just my 2 cents.

Thanks!