I had the same thought about the tires on my 5th wheel shortly after I bought it...until I realized exactly as donniedu pointed out. It sure is crazy scary how close them manufacturers cut it as far as tire capacities. And quality, or lack thereof, is a whole different issue!
'04 GMC Sierra 2500HD, CCSB, D/A, MaxBrake, B&W Companion, Retrax Pro, AR Power Steps
2013 Rockwood 8289WS w/Diamond pkg
1969 Camaro RS/SS Convertible
Dad's old 1968 Empi Imp (recently recovered from under 21 years worth of boxes/dust)