I currently I have a 2003 F150 XLT Supercab 2wd. I currently hace 235 70 R 16 on my truck and im gonna get 285 75R 16. The tire differnce between the two are 3 and 3/4 inches. BUt how much higher will my truck be sitting with the tires? Isnt that different?

 

It really depends on what PSI you run the tires on.

I would guess you arent going to be 3 inches higher, probably more like 1 or 2 inches taller.

 

if the tire is 3.75 inches more in diameter you will get about 1.875 inches more in height as only half of the tire size "lifts" the axle.
so basically what Johngs said.