I'm in the market for a truck, considering new and used, all "American" brands such as Ford GM and Mopar, and need it to be able to tow around 16,000 lbs which is the weight of the camper I'm looking at plus the stuff I'd keep in it, max of probably 16,200… I know I don't want to be maxing out the trucks capabilities, I'd like at least a 20 percent cushion, preferably 30 percent with how frequently I'll be towing. I know I'll need a HD truck as I've been told a 1500 can't handle a 5th wheel, and I'd prefer a diesel for the reliability, performance, and efficiency… I'm wondering if a second gen cummins could handle this, the 3500 quad cab dually, or if I'd have to look at the duramax LBZ dually or even the 09-now cummins dually or duramax LBL dually… I'm looking at the srw versions too, but from what I've heard drw is better for towing large loads. I'd prefer used, like 90's and early 00's so I wouldn't have a payment, or less than 10 years old so I can get a loan with a decent interest rate, probably 2 to 5 years old, but I'd consider new for the warranty and low interest rate as well… Must be a 4 door or extended cab, and must be able to tow up and down hill with 16,000 lbs at 55 plus mph, hopefully 70 plus mph on slight inclines and flat ground without trouble.