I believe this is my first post, but I've been lurking around here for a while. I've finally decided to put some new tires & wheels on my truck, and I need some advice.

First off...I understand backspacing, lug patterns, etc., but what is "offset"?

My truck is a 2006 F150 SC King Ranch 4x4. Here are the options I'm considering...

WHEELS - American Eagle 064 20 x 8.5; MotoMetal 951 20x9; American Eagle 178 20 x 8.5

TIRES - Nitto Terra Grapplers 305/55/20; BFG AT KO 285/55/20

I will probably also add a 2" AutoSpring Leveling Kit. I do not want to add fender flares, so I don't want the tires and wheels sticking out too far, but I really don't understand all the measurements of the wheels. Of course I want to avoid any rubbing. Also, I'm not sure how the 305 wide tires will work on 8.5 wide wheels either. Nitto's website says it will work, but...

I may also do an "add-a-leaf", but not sure at this time.

Any advice?

Thanks.

 

Offset and backspacing are two different ways of measuring the same thing. Off set is the distance from the center of the wheel to it's mounting surface (where it bolts to the hub). Backspacing is much simpler to understand. Also, a 285 or 305 mm wide tire will work fine on an 8.5 or 9 inch wheel. The Eagle's have 4.6 inches of backspacing so they will stick out about 2 inches farther than your OEM 7.5 inch wide wheels (which have 5.5 inches of backspacing).

 

Get the spacers and add-a-leaf kits. Your truck will still ride like stock and you get a nice boost up in the air.

From there, you have umpteen choices of wheel/tire combos. I'd look for no less than a 33" tire, with 34" being even better at filling the wheelwells nicely. I've noticed no major power loss with my tire/OE wheel combo (see sig).

305's will fit nicely on an 8.5" wide wheel. Heck, so would 315's or maybe even 325's. If you get this wide, front rubbing may be an issue with stock wheels specs, though.