Thanks for the reference info FE. I've seen debates on whether the axles have to be rated for full GVWR or if pin weight/tongue weight can be excluded. This regulation clarifies that the pin weight/tongue weight CAN be excluded.(EDITED TO CORRECT MY ERROR). Further details on my rig; it's a 2011 and is in compliance, right down to the yellow color of the weight sticker. Axles are rated 6,000 lbs, so the combination of 3 matches GVWR. Original tires were ST235x80-16R stamped with load rating of 3420 lbs @ 80 psi, so axle/GVWR is covered. We always dump tanks when we travel, except for carrying 5-10 gallons plus ice cubes in the black tank for pyramid attack.
How do they come up with GVWR? That's a good question. With 6k axles being a common selection, they could have worked to that basis for 18k. However, 7k axles are readily available. If nothing else in the design were changed, could the trailer then be 'declared' as 21k, or is detailed analysis of frame & other construction details done? Or, is it a marketing decision based on available tow vehicles which then leads to the axle selection and other details?
I would not assume that a retrofit of 7k axles would allow me to add another 3,000 lbs to the CCC.
