So I've got a set of Rancho quick lifts ready to go on the truck. I'm wondering what is the biggest tire I can fit on my stock 18" rims. The truck is a 2004 Screw Lariat.

I'm looking at GY Duratracs. My current BFG Rugged Trails are 275 65 18's.

The Duratracs come in 275 70 18 which I know will fit. The next size up would be a 295 65 18. Both are about 33 in tires. Would I be able to squeeze the wider tire on the rim? Would I want to?

 

4x4 or 4x2? Both will fit, but if your 4x4 you can go a little bigger if you want.

 

4x4

I think I read somewhere that the rim was 7.5" wide. I was worried I wouldnt be able to go up much more.

 

I wouldn't go wider than a 12.50" tire on the stock wheel, it's been done before but you gotta keep the air pressure right to prevent ballooning and uneven wear. I can't think of the exact metric size off the top of my head, but there's one that measures out to like a 34.5x11.50 which would fit nice too.

 

285/75/18 (34.8x11.5x18)
Toyo AT II and MT, Nitto Trail Grappler, Goodyear MT/R

295/70/18 (34.5x12x18)
Nitto Trail and Terra Grappler

 

Both of those tires will fit fine with the leveling kit. You can also fit a 305/70-18 (35x12.50), but they will rub the control arms slightly at full steering lock.

 

Thanks for your help guys!