spoon wrote:
Larry, I think you are right and I misspoke. FMVSS standards (I googled them) are for crash safety and crash avoidance. It has NOTHING to do with GVWR or axle ratings.
I forget what standard applies to vehicles to determine ratings. For some reason I thought FMVSS determined that.
Lots of opinions what the FMVSS says but this is a paste and copy from;
49 CFR
571.105 Standard No. 105; Hydraulic and electric brake systems.
S6.1 Vehicle weight.
S6.1.1 Other than tests specified at lightly loaded vehicle weight in S7.5(a), S7.7, S7.8, and S7.9, the vehicle is loaded to its GVWR such that the weight on each axle as measured at the tire-ground interface is in proportion to its GAWR, except that each fuel tank is filled to any level from 100 percent of capacity (corresponding to full GVWR) to 75 percent. However, if the weight on any axle of a vehicle at lightly loaded vehicle weight exceeds the axle's proportional share of the gross vehicle weight rating, the load required to reach GVWR is placed so that the weight on that axle remains the same as a lightly loaded vehicle weight."
GVWR and the GAWRs are mentioned in this brake test.
.......................................................
Also the truck GVWR and FAWR/RAWR are required for the truck makers to affix with a certification placard on the door post per;
49 cfr 567.4 Requirements for manufacturers of motor vehicles.
(a) Each manufacturer of motor vehicles (except vehicles manufactured in two or more stages) shall affix to each vehicle a label, of the type and in the manner described below, containing the statements specified in paragraph (g) of this section.
(b) The label shall be riveted or permanently affixed in such a manner that it cannot be removed without destroying or defacing it.
(snipped for length)
(3) “Gross Vehicle Weight Rating” or “GVWR” followed by the appropriate value in pounds, which shall not be less than the sum of the unloaded vehicle weight, rated cargo load, and 150 pounds times the number of the vehicle's designated seating positions.
(snipped)
(4) “Gross Axle Weight Rating” or “GAWR,” followed by the appropriate value in pounds, for each axle, identified in order from front to rear (e.g., front, first intermediate, second intermediate, rear).
..............................................
Keep in mind the truck maker may choose the trucks GVWR up to the sum of the certified GAWRs.
And brakes are a function of the trucks FAWR and RAWR but have to pass the minimum test at the trucks GVWR in proportion to its GAWRs.
Add your trucks fawr and rawr will be the brakes total lbs of brake performance.
Thats one reason some weight regulations may read like this one. I'm posting this as a reference to the vehicles brakes = the GAWRs and not to start a weights argument;
(snipped for length)
1. A person must not, without an overload permit, drive or operate on a highway a vehicle loaded or configured so that
(a) the gross weight on an axle exceeds the manufacturer's rated capacity for that axle or for the brake or suspension system with which the axle is equipped, ...........