According to the Mickey Thompson Tires website, here is the formula to convert backspacing to offset:

Backspacing – (Wheel Width + 1)/2 * 25.4 = offset

The XD Series Hoss Black 18x9 wheels list the following information on the 4WP website:

5.18 of Backspacing and 30mm of offset

If I do the math using the formula above, I get 5mm of offet, not 30.


Here is the formula to convert offset to backspacing:

For positive offset wheels: (Wheel Width +1)/2 + (offset * .03937)

Using this formula, I get 6 3/16" of Backspacing, not 5 3/16".


Are the formulas incorrect or is the wheel web site wrong?

Thanks,

KR-Texas

 

something is wrong all around there...I guess the formulas seem to work and get the same results as this chart, but the offset and bs of those rims doesnt go together....

 

Hawg,

Thanks for posting the chart, as it does validate the formula. The other wheels I checked were correct, but the 18x9 XD Hoss are the exception.

Now, the real question is whether the bs or the offset is correct?

I hope it is not 30 mm of offset and 6 3/16" of bs because I do not think they will work on a leveled truck without rubbing. I looked on several web sites and they all have the same numbers, so maybe the mistake came from KMC.

Thanks,

KR-Texas