Biggest tires on AT4 20" stock wheels with NO modification

Liquid Plumber AT4 · July 5, 2021

Just got the new setup installed and I really like the way it came out.

Went with the Fuel Sledge 20" X 9" +1 offset gloss black/milled wheel and the Toyo open country AT3 285/60R20 tire. Put the bilstein front coil/strut kit up front which leveled the truck off almost perfect and the bilstein rear shocks which took away that back end bounce feeling over bumps.No trimming at all needed, I get a very slight rub at full turn in reverse on the front splash guard and just barely.....but these are the bigger GMC splash guards. Im going to try to swap the front splash guards back out with the ones that came with the truck to see if it helps, if not I might try those gatorguard mud flaps. Also this setup cleared the A-arm with plenty of clearance. I have about 3/4" to 1" of poke which is perfect and not to aggressive.

I definitely feel like with the bilstein front strut/coil kit which brings it up 1.2" in the front on the #3 circlip setting that a 285/60R20 tire is the max you could do without getting into trimming or having major rubbing. I am very impressed with the toyo open country AT3 tires....they are meaty for an all terrain tire and very quiet. I found the sweet spot is 38 PSI on my truck to run.....toyo recomend 40 to 42 but they rode stiffer at 42.

Here are a few picures of the outcome

SpeedySierra · May 6, 2022

I know this is old thread but it helped me. With sizing. I have some 275/65/r20 Firestone Destination XT on stock 20 wheels.

vanilla ice · February 5, 2023

Bringing this thread back from the dead.

I would like to see if anyone has 295/65r20 on a stock AT4. I just ordered AMP 295/65r20 for my ‘22 Sierra 1500 Elevation 3.0 I have a factory 2” lift that was installed by the dealership (warranty forgiveness, long story) and I now match the same height as a stock AT4.

I seen some sierra 1500’s with 295/60r20 with a 2.5 level.

Just not 295/65r20.

Thank you in advance!

Josh021 · March 21, 2023

2020 elevation with factory level And 2" readylift sst. Currently running 275/65r20 destination xt. Removed splash guard and steps put a regular flap for now. Waiting on my 35s.