It will easily haul any loose material you can fit in the bed up hills that are 20 degrees plus. I hauled dozens of loads one weekend from the lower part of my building lot to the upper part so we could backfill. I guess it was 600-900# of loose clay/dirt per load. It was over 20 cubic yards.
Someone can do the trig for me, but it was roughly a 100' trip straight up the hill and a 20'-24' rise in elevation. My lot is only 2.5 acres, but has a 90' elevation difference from the front corner to the back corner.
Never a whimper and no sign of running out of power. I did have the 4 wheel switch turned on in case it needed it.