Compelling reason is putting 800 - 1000 pound motorcycles in the back when they need to be "rescued". I have done this several times recently. The old truck really squats when I load it up. I know I am still within capacity, but was looking to beef it up a bit. Not trying to make a 3/4T out of it, just give it a bit more gusto.
It's not something I would do on a regular basis, but nice to know it can.
