Now before you get your knickers all in a knot; I AM NOT casting stones at anybody for their beliefs. I respect your right to have any beliefs with which you are comfortable and happy. Please don’t take offense because I might disagree with your beliefs. I'm always willing to participate in rational discussions and sincerely hope this is one of those.
I know I’m just a newbie on this site, but I’ve been an RV’er for a good portion of my adult life (70 years young and counting) and have owned everything except a Class B motorhome. I’m always glad to learn new stuff from others as well as share my knowledge when appropriate. I’ve been a Trailer Life/Motorhome Life Magazine subscriber for a long time. I’ve talked with truck dealers and truck owners all over the USA about GVWR limitations and have come to the conclusion that very few people REALLY have a handle on GVWR and what is really involved in calculating this figure by the manufacturer of the truck.
What I’ve learned over the years is this; the GVWR takes a lot of components into consideration that include but are not limited to the entire drive train (engine, transmission, drive shaft, axles, suspension system, frame, wheels, tires, etc). Each manufacturer has a different methodology for computing the GVWR and it is highly unlikely that any two will be the same. And because there isn’t one standard used by all manufacturers, it is very difficult to intelligently determine which truck actually has the highest GVWR.
Sure, they all put a tag on the vehicle that tells you what the GVWR is and a call to any manufacturer will get you an actual payload for that truck as it left the factory. But that payload figure will be changed every time ANYTHING is added or removed from the truck. Add a receiver hitch, remove a tailgate, add a 3-ball mount or hitch extender, add running boards or nurf bars, switch wheels from steel to aluminum, etc., etc., etc. The only way to know for sure is to weigh the truck as you own it with a full tank of fuel.
And can you change any of the factory components to increase the GVWR as stated on the factory tag? That all depends on who you talk to and who you believe. If you talk to ANY factory representative, the answer will most definitely be no. If you talk to any of the technical representatives writing for publications that cater to the RV’ing public the answer will be no. If you talk to RV’ers driving trucks and hauling trailers and campers the answers will be some yes and some no. Why is that? I don’t have a clue.
Some believe and will tell you that you can increase the GVWR by going to a bigger and stronger wheel/tire combination. Some will tell you that you can increase the GVWR by replacing the axle with a stronger model. Some will tell you that the factory figures have a built in safety factor of some percent value and you can exceed the GVWR a little and still be safe (do not try to tell your insurance company this – it won’t work). These same folks will also tell you they have done this and have ‘x’ number of miles or ‘y’ number of years doing it this way and have never had a single problem or breakdown. Well, I know some folks that smoked their entire adult lives, lived past 80, and did not die of lung cancer. That doesn’t mean that smoking isn’t, in fact, related to lung cancer.
In case you haven’t figured it out by now, I’m one who believes that whatever truck you own, you are limited to whatever GVWR is on the factory tag. If you need a higher payload capacity, you are going to have to buy a higher capacity truck. You can add all sorts of aftermarket gizmos and whiz bangs to make the truck perform better, run more efficiently, eliminate or curtail yaw, pitch, and roll; but you can’t change the GVWR by adding or changing a couple of weight bearing or drive train components after market.
If you have knowledge of, or access to, any reputable, scientific studies that say otherwise, I’d really like to see them. I’m always eager to learn and educate myself.