I've got 20x8.5 Liquid Metal Magma wheels on my '05 F-150 FX4. They have 5.75'' backspacing with a 25mm positive offset. I installed the 2.5'' leveling kit and I'm dying to get some mud tires on there. I would like to fit the Nitto Mud Grappler 35x12.5, but some people say you can't do it, some people say it's hit and miss depending on the brand and type, some people say they have done it with minor if any rubbing. Can anyone point me in the right direction?? I know I can't get too crazy with the width with 5.75'' backspacing, so I'm hoping 12.5'' will do the trick. What is the perfect offset and backspacing on aftermarket 20" wheels? I've also been looking into 305/60's and 285/65's. Would someone like to throw some brands and dimensions at me that will actually work? I would appreciate it. Thanks!

 

you want as close to oem spec's.

 

I vote: Rub

 

i'd say rub too, especially with grapplers. now i'm sure you can live with the rubbing on a 285/65/20 or 275/65/20 which is a tad smaller.

 

I think you may be able to squeeze a 35x12.50 on there using those wheels with some minor rubbing. However, the Mud Grapplers have huge sidewall lugs and they may rub the upper ball joints constantly. I'm sure they will rub the control arms badly at full steering lock. The Muc Grappler performs fine, but there are a lot better choices. The Mud Grapplers are extremely loud and wear out quickly. A 325/60-20 is basically a 35x13.00 tire and would be too wide. A 285/65-20 is basically a 35x11.50 tire and would be your best chance at fitting a 35 with those wheels. BFG makes the AT KO in that size and it is one of the best AT tires available.