The guy in the Chevy was shocked when it did it. I was pulling a small hill here in town with my 5th wheel loaded about 8k. I started to pull the hill the guy in the chevy tried to out power me well.......my truck down shifted down to 1st and the wheels started to break loose. I had to back out so I did not break something. I got to the top of the hill and the chevy guy pulled up next to me and had that O'sh&t look. Got to love POWER.....