Does anyone have experience running oversize tires on 2011-and-up SD's? How big can you run with no lift?

I'm looking at Goodyear DuraTrac in 325/65-18 (34.8x13) with max load capacity of 3,860@65 or Goodyear MT/R Kevlar in 285/75-18 (35.1x11.3) with max load capacity of 4,080@80, both technically load range E. I will be occasionally pulling a gooseneck of about 15k lbs. I will also occasionally have to deal with mud (by necessity not for fun). I realize both will fit in the wheel well with plenty of space to spare, but I'm not sure how wide you can go without rubbing at full lock on the stock 18" Lariat wheels.



My 2011 6.7 PSD came from the factory with the 3.55 gearing and 34's (275/65-20 = 34.1x10.8"), but the dealership agreed to swap them with another truck that had the 33's (275/70-18 = 33.2x10.8") because I liked the look of the wheels better since the Sterling Gray paint between the mags/spokes matched exactly the Sterling Gray paint on the truck and because generally 18" tires are cheaper than 20" tires and with more options. Plus oversize tires on 18's "look" bigger, which is nice, too.

I got this truck for driving daily and pulling 5th wheels and Jeep-laden goosenecks. I have no desire to lift it, and I installed Firestone bags and an Air Lift wireless compressor setup myself, which means i don't want to have to re-do any of that either.

Anyway, I'm thinking about bumping up to ~35's. I would rather go to 37's, and I'm pretty convinced that 37's can fit with no lift and no modification on the enlarged wheel wells of the 2011, other than maybe bump stop extensions. But that starts to push the limits of stock equipment when it comes to longevity, gearing, and braking. I do NOT want to have to re-gear. I have a rock crawler Jeep for big stuff.

Honestly I'd rather have the MTR Kevlars but think it would look nice with the DuraTracs as well, though I'm not sure how either would be on the road at first or after some wear has been put on them.

 

37's will rub like crazy. I have 295x70x18 on mine and they dont rub. There really isnt space to go any bigger without a lift of some sort. I have a 2011 f350 6.7 L. The tires are nitto trail grapplers. Tires are great,load range E, and wear nice.

 

If you go bigger than 35's it will look silly even if it doesnt rub, which it will. Those sizes you mentioned you were thinking all sound good to me. The 325 65 18 sound the best as far as size IMO. A nice wide tire. Just one man's opinion.

 

I was considering 37's on my old '07 6.0, and they looked fantastic with no lift, but they did require some slight trimming of the bumper. With these new bigger wheel wells I kind of figured no trimming would even be necessary.

Either way realistically I think 35's will be plenty and still look great. If even the wider tire fits fine without rubbing arms or coil buckets or whatever, then I think I'm all set.

I am curious as to how people have done with DuraTrac or MT/R Kevlar tires on DD/part-time-haulers. DuraTracs look like they'd do well but those kevlars are awesome rock and mud tires and looked fantastic as 35's on a buddy's '06. But he never really pulled anything with it but his big ***

Here in south Texas I also have to worry about some wicked cactus thorns, enough to pierce the sidewall of my old Nitto Terra Grapplers (yes load range E) and even between the tread of my old Acrtic Cat Carlisles... Which makes me think the Kevlar in the sidewall is probably a good idea...