Larger tires for my 04 F150

[cbacchi0]

I have replaced the stock tires on my F150 (235/70R17) with larger tires (265/70R17) and was told I will have to get the computer in the truck modified. Is this completely necessary, or will the difference be so small I won't notice?

 

[ronjon21177]

The only think that i could think of is to correct your speedometer . reason being the bigger tires will tell
you that your going say 55 mph but your really going 56 or up to 60 mph. with smaller tires it will read
55 mph but your only doin say 50 mph.

oh to let you know the speedometer is computer controlled.
older models are drivin by a cable at the out put drive axel shaft. / >-

 

[hillbilly]

I have replaced the stock tires on my F150 (235/70R17) with larger tires (265/70R17) and was told I will have to get the computer in the truck modified. Is this completely necessary, or will the difference be so small I won't notice?

265 is the tread width, 70 is the height. you didnt change the height. thats what screws with the comp.super chip makes a box to correct tire height and gear changes. I dont think you need one though. this is important when changing tire height or gears. its not just your speedo, its air fuel, timing,shift point,o/d . from the mountain hillbilly