I wonder why proponents of ignoring GVWR ratings are usually adamant about not exceeding axle or tire limits . Wouldn't these have the same safety factor built in ?
Proponents ??
Your talking about the entire trucking industry as the truck makers GVWR isn't used to determine if a truck is overweight.
As Wayne pointed out there are mechanical spec sheets available from the truck makers for anyone to see and read. Fleet Ford is one of the easier websites for pros and newbys to gleen mechanical specs on LDT size trucks.
https://www.fleet.ford.com/truckbbas/topics/2016/specs.html.
Things we know are the truck makers may choose any GVWR they want and may be up to the sum of the GAWRs per FMVSS.
A mfg Example;.... Ford spec sheets tells us (quote) "4) Gross Axle Weight Rating is determined by the rated capacity of the minimum component of the axle system (axle, computer-selected springs, wheels, tires) of a specific vehicle. Front and rear GAWRs will, in all cases, sum to a number equal to or greater than the GVWR for the particular vehicle." (snip).
Ford also gives us a F350 SRW with a 11200 or 10000 GVWR in the exact same truck. Its all in the clicky.
I'm using Ford as a example simply because their website makes it so simple.....compared to a wad of websites/PDF files required for GM and Dodge/Ram.