I'm buying a new 2020 and want to go with bigger tires. I have read where some guys have used 35 x12.5 x 20 tires with now leveling. I have also read where some have used 37 x 12.5 x 10 with a leveling kit. I want to use 325 /60 r20. They are wider than the 12.5 and taller than the 35s. Will this tire work without leveling?

Well you may not depending on where you go to mount your tires be able to do what you are wanting (I use Discount Tire). Times have changed over the last couple of years. The tire shops at least the national ones and the mom and pop ones who have insurance companies that they stay in compliance with their policy with will not do the 325 and SOME of the 12.50 tires on the factory wheels.

Each tire manufacturer has listed the min and max for rim width on a specific tire and they are all different. The wheels on my 2020 Denali are 8.5 wide SO I was lucky that the 35x12.50-20 Ridge Grappler shows 8.5 wide and was the minimum allowed.

Now going with aftermarket wheels that are wider will fix this.

Reason for this is simple---in any kind of accident the company that mounted the tires would be potentially at risk and in fact be sued along with everyone else. Personally know of someone who this happened--was a roll over two people died.

I did notice that the minimum width rim on a 325 is 9". This wasn't a big deal for me because I'm planning on going with aftermarket rims in the near future. I will ask the Goodyear dealer if they will mount them though. I really want to know if they will fit without rubbing at stock height. How much extra room do you have with your 35x12.5x20 tires?

Well I have the Snow Plow Package so the front end is stiff baby. I use my 4x4 at the ranch in full articulation and have only had a couple of Very Very slight rubs that you heard and did not feel and they left no marks. The 325's would not work on my truck but for a mall crawler most likely very small amount of rub under specific conditions like turning into a dip going into a parking lot with the wheels turned almost all the way.

If you had to guess, would your tires rub at the tread or sidewall? I'm wondering a wheel spacer could correct a rub issue or if I would have to crank the torsion bars.

Where mine rubbed during turning and suspension articulation I do not know what to tell you because I think the edge of the tread will still impact the back of the wheel well during a full or close to it with suspension articulation. Never used a wheel spacers usually go with BDS suspension systems and different wheels. This truck did not require that to get around on the ranch after getting rid of the running boards.

I would love to run the 325x60 tires but to do so the right way will set me back about 10k for wheels and suspension. I keep trucks only 2 to 3 years max (100k to 125k) then time for another one. Not going to spend the monies modify the suspension on this one when it is not needed. Definitely a selling point with me--so used to having the parts already at my 4wd shop and driving the truck over there for a couple days worth of work. This time had a set of lower profile higher up step boards installed https://www.roughcountry.com/gm-cab-...-srb01900.html they lasted one trip to the ranch and went with the HD AMP steps problem solved.

Buddy of mine installed 35x12.50r20 on a 2020 Denali and had to turn the keys very little he said for it not to rub. 325/60 can easily be done just depends on how much you are willing to turn the keys/ trim. A local shop here just installed 37x12.50s on a 2020 with a suspension max leveling kit and full throttle suspension control arms. Not sure if they had to do any trimming tho. Personally i think these trucks need 37s on them to look proportional with the larger body they now have. The shop was Dealer Options in Augusta, Ga if you want to call them to see what all they had to do. Was a black GMC Denali hd for reference. I saw it on their Instagram page & I think they have a facebook page too if you have either of those.

I saw that video of that truck on YouTube. I agree with the truck needing bigger tires but I use mine for towing so I have to keep it down at close to stock height. The 325s are 1/2" wider section width, 1" wider tread width and 1/2" taller than the 35 x 12.5 x 20. That may be too much unless I could wheel space it out or something. I personally don't want to level it because my trailer does that. These trucks are pretty new so not too many are changing tires yet or at least not posting it.

I should ask you guys if you changed the tire pressure value on your computer to read the lower pressure tires? If so how do you do it?

With a tool that the tire stores have.