I am looking into getting a 6" lift and some 18's on 35" mud terrains. Im am getting the KMC monsters but not sure what offset and backspacing to get and what the difference will look like. They are available in either 18x9, 6x135/5.5 OS: -12mm BS: 4.53" or 18x9, 6x135/5.5 OS: 18mm BS: 5.71". Any help or pictures would be greatly appreciated. Im new when it comes to this stuff

 

A 9 inch wheel compared to your OEM wheels would work out like this:
5.5 inch BS would stick out 1.5 inches farther
4.5 inch BS would stick out 2.5 inches farther
5.7 inch BS would stick out 1.3 inches farther

 

Depends on what brand lift you use. Skyjacker requires no more than a 4.5 bs. I think procomp and fabtech allow for a 5" bs (may be wrong about that, but sure about skyjacker). decide on a specific kit then look on there website and it will tell you the largest BS/offest you can run.

 

The lift i am getting is the Fabtech 6" Performance System w/ Dirt Logic 2.5 Coilovers & Performance Shocks - 2004-08 Ford F150 4WD

http://www.fabtechmotorsports.com/pr...lay=FORD%204WD

Their website says "Use 325/65R18 tires w/ 18x9 wheels w/ 5” BS w/ minor trimming"
Does this mean the 4.53 backspacing wont work?

Thanks for the help!

 

4.5bs will work. It will not go as deep into the fenderwell. The larger the BS the futher into the fenderwell the rim will go. You go always go with less bs just not more.

 

Not meaning to hijack here but the stock wheel size on an 04 to 08 f150 is 5.5" of backspace. If i were to buy a wheel that had 4.5" of backspace it would work. It would just stick further out under the wheel well? About an inch or so?

 

The backspacing is only part of the formula. You have to know the wheel width AND backspacing to determine fitment.

 

Ok so lets say they're 17x8" 0 mm offset with 4.5" backspacing wrapped in 285/70/17. They should fit but stick out roughly an inch or so?

 

An 8 inch wheel with 4.5 inches of BS will stick out 1.5 inches farther than the OEM 7.5 inch wide wheels (which have 5.5 inches of BS).