Unlike most people here I leveled my 06 4X4 by lowering the back. I use my truck to transport dogs, and this height works much better for me on a day to day basis. I currently have Michelin 255/70-18 tires on stock Lincoln wheels, which are just about like stock 18" KR wheels. The diameter of the tires is ok, their roughly 32's but I'd like to go up to 33's and would like to put the widest tire possible without rubbing. Looking at many of the posts on the list I'm thinking I might be able to get a 285/65-18 to fit. I am looking for some input on tire sizes, and hoping I'll be lucky enough to get the tire guru Wandell to chime in.

Thanks

 

The FX4 comes from the factory with 275/65/18's, so you could probably step it up a little from there. I bet the 285's would work alright, but may look a little large on factory/lowered suspension. There is plenty of room in the rear wheel wells so don't be worried about rubbing back there because it is lower.
A smaller 275 would work better if you've got 3.55 gears, but a 285 shouldn't be a huge tax on the drivetrain either.

 

Thanks Brian. I knew the FX4's came with the 275/65's, I just wanted to stuff the widest tire I could on the stock wheels and in the fender wells with no rubbing. The 275's are about the same height as the 255's, but are wider so maybe I will just stick with that and avoid any potential problems. I do have 3.73 gears by the way.

 

You will be able to fit a 285/65-18 (33x11.50) or a 305/60-18 (33x12.50) easily using the OEM wheels.

 

Thanks wandell. The stock rim really sucks that 12.5 in, doesn't it? I kind of thought 11.5 would work, but did not think 12.5 would looking at the available clearance I currently have. So how open are tire shops to mount a tire on a wheel that's considered too narrow by the tire manufacturer? Does this affect the warranty?

 

Yes, it can affect the warranty since most 305mm/ 12.50 inch wide tires recommend an 8 to 10 inch wide wheel and the OEM Ford wheels are 7.5 inches wide. However several members here have done it with no problems.

 

Thanks man.....a little food for thought.

 

If you run a 12.5" tire on stock wheels (I am) you'll have to keep the pressure down a bit to get even tire wear, but it has been no big deal for me. In my 35x12.50R18's I run 38psi front and 34 in the back, and rotate them every 3000 miles. So far they are wearing great with 15k miles on them.