I have an 07 Yukon XL and have had 24's with 305/35/24 tires for the past month now. The ride is fine, smooth, a tad rough over bumps but nothing seriouse. The only major draw-back is a little heavier(of course). Gas mileage changed a tad on the "instant MPG". Rolls down to v4 less now that the truck is heavier. I did rub in the front inside the fender wells against the black plastic when I would make a FULL turn(forward & reverse) however its now worn down the plastic and no longer rubs. As for clearance, from tire to fender I have plenty! More than 6" in the rear and 4" in the front. I too pull a load(4 quads) and have no problems. Hope this helps!