I have been down this road, since I put 28" on 12" bead locks with 2" lift, I blow through trails I normally had issues with stock setup, Took unit in for yearly checkup and all fluids look good. Local mechanic sees lots of dark trans oil form 30" tires, unless you are on open/hard packed trails, bigger tires work, if you are on soft trails with lots of low torque climbing, 28" the biggest you want to go. I went with 12" bead lockers and it rides nice on rough trail and has plenty of flotation on soft muddy trails. Stay away from radial tires unless you are looking for DOT public road riding. My buddy has DOT truck tires (skinny) and he is always wanting me to drive ahead of him so I can pull him out easier. I just leave me tow rope on receiver.