Which offset???

[one5oh2nv]

Bought a set of kmc wheels, but not sure they are the right ones for my truck. Researching now I see they have 20x8.5 with a +18 offset and the 20x9 with a -12 offset. I have an 03 f350. which ones do I need?

[shawnb99]

+18, you need 4.5 inches of bs......the -12 on a 9 gives you 5, that would rub the leaf

[one5oh2nv]

I have the 8.5's which is the +18 and they have 305/55/20 toyo at's and they rub! so should I get spacers or sell and buy new ones?

[tmanscrew]

I am pretty sure positive(+) offset gives you less backspace, in other words the dish of the wheel is set more to the outside of the wheel and the wheel sits further under the fender well. Negative(-) offset is the opposite. The wheel will stick out further, which will give you more backspace. Pretty sure I am correct on this.

[one5oh2nv]

tman Im sure your correct! So basically I either need new wheels or some spacers! Bummer!

[04cr450]

I have 20x12 fuel hostages and 305/55/20 on my 04 f350 with leveling kit.. -44 offset meaning 4.5" of backspacing and they do even come close to the leafsprings. The rub on the front fender a wee bit