iLL6031

Ok so I have my lift kit on order. (6" Lift). I usually try to read as much as I can without asking a question to make sure it hasnt been asked before(and im sure this has but I could not find really my exact answer). When reading these lift and wheel threads is backspacing and wheel offsets. I honestly just dont understand it. ive read people with different wheels but same trucks with different offset numbers ect. I want to put on the XD Misfits in 20s with more of an All terrain tire, nothing to meaty but looks good. Ive been looking at the nitto terra grappler and it seems like its a good combo. But I totaly do not understand the backspacing/wheel offset. I would assume its to have the wheels not rub but how do you figure it, I know theres a calculator on here but like I said i just don't get it. and after that how do you go about making that offset. Any help would be appreciated, thanks

06F150CFCT

Here is a good chart that i like to use...rim width is on the y-axis and rim backspace is on the x-axis.





Depending on your lift kit manufacturer they will require different specs on rim sizes. Most will require a rim with 4.5" BS which is a -12mm offset on any size rim that is 9" wide. This is so the rim will clear the new knuckle and not rub when putting on the 35" tires that are usually recommended. Some kits you can run a 5" backspace wheel which will be tucked in closer to the truck.
The lower the backspace number (ex 4.5"), the farther away ftom the truck the wheel will stick out. The same goes with offset...The lower the number (ex -12mm) the more it will stick out. The offset is directly related to the backspace and the wheel width though. So now the opposites are also true. The higher the backspace number (ex 6", which is about what your stock wheels are) the more they will fit tucked in the wheel well.

An example would be the stock 20's on a King Ranch are 20x8.5 with a 6.14" backspace and +44mm offset. These wouldnt be good to run with a 6" lift because they are tucked in really close to the truck and would rub the knuckle when you put on the beefy tires.
So depending on your XD wheel width, look at getting them in a 4.5" backspacing, possibly 5" but i wouldnt go any higher as you might start rubbing when you put the tires on.

These pics show offset and backspacing and describe it in pictures if you are a visual learner.

iLL6031

wow, lots of info, thanks! I think I sort of understand it now, so its pretty much all directly related to the lift kit you put on it for starters.

Now I went with http://www.roughcountry.com/ford_4wd_f150_6.html

It says in the Info:

Wheel Backspacing: 4.5"Recommended Tire Size: 35x12.508" wide wheel is recommended.
Does that mean I have to find the XD Misfits (Which is the wheel i want) in and 8" wide, and do I tell them the offset at the wheel shop when I order or Will they know, or is it something done on the install? With the 4.5 that will mean my wheels will stick out alot yes? I dont mind some out but not a TON. ya know?

06F150CFCT

You can get the 9" wide XD's...The lift kit companies always low ball their numbers so they fit 100% of the time. They dont wanna deal with people complaining that there was rubbing when they installed their tires. You will be fine with the 9" and i wouldnt try to fit a 12.5" wide tire on a 8" rim. When you order the wheels, each size should have its own part number unless you order them from a store on ebay (cheaper) then i would make sure to specify the size of backspacing and offset.
The 4.5" BS wheels will stick out a decent amount from stock especially when you get the wider tires...itll be about 1.5"-2" more than stock.
I have fender flares on my truck so i dont have a good picture to describe what i mean. My tires are almost flush with my flares and they are 2" wide.

06F150CFCT

This is when i had a 5.5" Backspace wheel right after i installed my lift and right before i did the flares. Stuck out about 1" with the 9" wide wheel and 11.6" wide tires. So you are looking at realistically 2"-2.5" more over stock.

06F150CFCT

This is now with 37x12.5 tires with a 9" wide wheel and the fender flares. They dont stick out from them much if at all.

iLL6031

ok cool, thanks for the pics and help, I apreciate it. So from the looks of things i should be fine with that wheel setup I take it.

iLL6031

I also belive that the misfits only come in a 0mm offset, so the width of tire would be how much it sticks out after that correct?

iLL6031

Thanks for all the help man apreciate it. I actually just left the store and ordered some 20" misfits with Toyo Open Country AT2 Extreme 35 1250 20.

06F150CFCT

Perfect...thats gunna look sick. Good luck!