What determines payloads?

Flashman wrote:

Grit dog wrote:

ShinerBock wrote:
Payload is determined by subtracting the trucks weight from it's GVWR.


What you really should be asking is what determines a truck's GVWR. For that, there are different answers for different truck classes.

^This.
For all the other factors going into the gvw, it's not only different for different truck classes, but the limiting factors change by make/model/year.
IMO, in general, class 1 trucks are often limited by Marketing, considering you can upgrade tires easily. Knowing that a lot of axles are rated for more weight by the mfg if they're not in house axles.
Class 2, more of a gvw limit for licensing usually as they are typically the same chassis as a class 3 maybe with less springs.
Class 3, tire capacity for srw followed by axle capacity for drw is more prevalent.
Bottom line, if you don't understand the mechanics and limitations of the vehicle components, then use the mfg payload cap as it typically has a healthy margin of safety in place thanks to the lawyers!

Fixed

Fairy dust

Actually he was right. Class 2A (half ton ; 150/1500) trucks are mostly limited by their softer suspension in many cases. Although in some cases it might be other things. Take Ram 1500s for instance that do not have a GVWR higher than 7,000 yet the class they are in allows them to go to 8,500 GVWR. Most other manufacturers have a GVWR higher than 7,000 lbs. Why they do not increase it I do not know for sure, but I do know Ram 1500s use smaller axles in general with smaller axles shafts and only have 5 lugs to where all other Class 2A trucks use 6 lugs. So I am not sure it is the axles or suspension limiting them to such a low GVWR for it's class.