I just purchased an 04 fx4 supercrew, with 5.5 ft. bed and 18" wheels last week. I am looking to upgrade to a larger tire that will look better, give a little more cleearance, and be versatile enough to go 4-wheeling through mud, snow, boulders, etc. yet still perform well at higher speeds on the highway. Does anyone know what is the largest tire size that will fit practically on this truck with these wheels and no leveling/lift kit. I would like to get them from a place that will buy the stock tires from me as well, if anyone has any suggestions/ideas about this please reply...Thanx!

 

Try Tirerack.com.

 

your going to have to go to a smaller probably locally owned place for them to buy your tires. their prices are probably more than places like discount tire co. discount also has the hunter machine which works great and a lot of people have been complaining about shimmies and vibrations.

 

Your problem is the 7.5" wide rims the truck came with. The 275 x 65 x 18" rubber the truck came with is as big as fits on those rims. BF Goodrich has a 285 x 65 x 18, they recommend an 8.5" rim minimum. If you go with a tire that needs a wider rim you'll need to run it with less pressure if you want the outer treads beads to wear. There just are not allot of 18" tires out there yet.. You can do lots better if you drop back to 17" rim and buy it at least 9" wide..


http://www.tirerack.com/tires/index.jsp Has all the specs. Pay attention to the rim width requirement..