http://news.pickuptrucks.com/2014/07/more-game-playing-now-gm-fesses-up.html Not surprising. Ram will probably next. Or maybe not. Time for another standard for payload ratings.
Much ado about nothing. How much does the bumper weigh? Maybe 50#.
As for the tires and wheels, that is unsprung weight, so the only way for that to produce a higher number is if the tires/wheels are rated to carry more weight.
