Anyone have any idea whats the largest size tires I can put on my 94 F150 4x4? And if I do put bigger tires on will they scew up my speed sensors and speedo etc? I would like to put 31s or 33s on without having to do a suspension lift but do not want to screw up the computer on this thing. TIA

 

Changing the tire size wont screw up your computer but it will affect your speedo accuracy.
Bigger tires will make your speedo slower than acutal. stock to 33's will throw it off around 10% (60mph reading will be 66 actual)
I think Kelly's drivetrain home page has a speed/rpm calculator you can use.

 

I belive you can run 32x11.50's stock, but you'll probably rub. I'm running 32x11.50's on 15x10 rims with a 4" lift on my 90 F-150 4x4 (which I think looks good). The only problem is she seems a bit sluggish, and the speedo's off by about 5-6 MPH (reads 54 when going 60).

 

I have 32 X 11.5 BF goodrich AT's on my 88 F-150 4X4 and they don't rub unless I am turning really sharp then they rub the lower arms on the front but not badly. I really like the tires, they only screw up the speedo 5-6 mph (I just had it checked) and it is worth the upgrade.

Now I just gotta get some real shocks! The Napa blues I got ride crappy.

Later.
Randy

 

You can put 31x10.5's on with no rubbing problems at all. Your speedo will be slightly off, you may also notice some reduced power pulling away from a dead stop (depending on how your axles are geared) and your city gas mileage will likely drop some. The 31" tires need to be mounted on 7 to 9 inch wheels.

1992 F150 Supercab SB 4x4 302 AOD 3.55 31x10.5 All Terrain on Ford 15x8 Ralleys