I have an 08 F250 6.4L. I've been looking to buy an aftermarket 20x10, which has a -20mm offset. I was going to run a 33x12.5 on it but was told that with that offset it may hit the fender even with a leveling kit, I guess the oem wheel only has a offset of +48mm so I'd be moving my wheel out about 3in plus the extra 2in of rim would make it about 4in wider. What is everyone else running? will this set up work on an 08 superduty? I know a guy thats is running a -18mm offset 20x10 on an 06 F250 with no problems, would 2mm really make a difference? Please help.

 

You did not mention if your truck is a 4x2 or 4x4, so I will assume it is a 4x4. You are moving your wheel outboard 28mm which equals 1.1 inches. Plus the two additional inches of wheel width (because the extra width is already taken into account when measuring backspacing you have to add the additional two inches outboard) which equals a total of 3.1 inches of additional rim extending out from the hub surface. The 33x12.50 tire should have a pretty square profile on the 10in rim and not overhang very much. I would guess you would not have any problems running the rim/tire combo on the 08 body style as they have larger wheel well openings than the previous Superduty's. With a leveling kit, I would think you would be more than clearing what you want to do. If you're still in doubt, take a 3.1 inch thick piece of wood or something 3.1in thick, and tape it to the outside of your tire where it would rub the fender/bumper and turn the tire and see how close it gets on both the front outer, and back outer of the front tires. You can also jack up the front suspension to where it would be sitting with a leveling kit and do the same measurments. Just remember, measure your existing tire height and compare that with the new tire. If it is larger, then add that to your measurments. Lastly, not all tires are created equal. Look up on the tire manufacture tire sizing chart, to see what the actual measurment is for the specific brand tire is including your own. My Toyo's in the exact size as the BFG were taller and wider. Hope this helps.

 

Superairdave, how wide are your rims and what offset are you running?