This forum seems the best fit for this topic: Authority Having Jurisdiction (AHJ) when it comes to weight regulations. This would apply to every vehicle but it really hits home with the Super Duty trucks. These days with the weight rating and power wars and the ever increasing size of our socially acceptable toys we have ran up against the 1970's era regulations that most, if not all, states have.

My comments are simple: The DOT is the AHJ on the roads and Ford is the AHJ in their repair shop. What I mean by this, in particular, is the Gross Combined Weight Rating of a truck is not recognized by the DOT however, if a owner exceeds this value then warranty work can be denied. On the other hand, the Gross Axle Weight Rating from the manufacturer is what the DOT looks at. Almost every thread on this topic you will have some who pipes up and run scared of litigious liability for exceeding any weight ratings. In a court of law the DOT regs will carry the weight (excuse the pun). The DOT is looking after the welfare of the road itself and the others sharing the roadway. The DOT cares about if the axle will bear the weight and if it will stop that weight.

I have an F550 and am about to replace it so I ran all the numbers and why this topic is on my mind. To my surprise, currently, the GCWR can be the same between the F350, F450, and F550. Well then.... what is the difference? In a word "payload" or the rear axle weight carrying rating. Not only does this matter for an upfitter's bed requirements but it also affects trailer tongue weight carrying ability. The DOT sees a truck and its trailer as two separate vehicles and adds both manufacturer rating together to get their GCWR, this is in contrast to Ford that peg it at #40K lbs. So, you can be legal (and safe) and the only downside is you may be declined warranty work however, how is Ford going to know unless your dumb enough to show up at the dealer with the load still attached. For example with a F550 you can get 7,500 front axle, 14,700 rear axle, plus whatever trailer you buy say, a dual tandem with 15,000lb axles you get a GCWR of 52,200 lbs. by the DOT. So, you can gross ~50K legally and safely if loaded correctly. Before you get all riled up and remember this, do you know more than the DOT?

To recap: respect the individual axle ratings that Ford gives because this is what the DOT looks at but, the GCWR (Gross Combined Weight Ratings) does not carry weight (there's that pun again) with the DOT.

 

Good summary, and frustration shared.
One different perspective, though. The DOT does care about the GCWR, because that is what drives the requirement for a Class A/B license. The requirements vary state to state, but in most states if you drive a superduty and pull a (non-rv) trailer with a weight rating over 12,000lbs (for duallies) or over about 15k +/- for SRW trucks, a class A license is required regardless of actual trailer load. When the GCWR exceeds 26,000lb, regardless of actual weight, and it is not an RV, it is class A license or park it where you got pulled over until a class A driver shows up.
Lots of legal loopholes and other BTWs, and significant variance by state of course.

 

It is very complicated. A few years ago i was researching DOT laws for my construction/remodeling business to see what would be required. I Have my own rule of thumb..my 2016 f250 @10k pounds which is the max it can be registered for and towing a max 10K pound trailer.
What gets me is an RV gets a free pass..to me towing is towing.

 

 

Let me add one item of importance that DOT can and may look at: Tire ratings.. Not only does your registration have to be correct and your axle ratings, but tires have to be able to carry the load as well.

 

 

 

I understand your point, but I still think a good lawyer can make a case for negligence by grossly exceeding the manufacturer's rating. Which could then also lead to an insurance claim denial. It's a litigious world we live in whether you agree with it or not.

 

For example with a F550 you can get 7,500 front axle, 14,700 rear axle, plus whatever trailer you buy say, a dual tandem with 15,000lb axles you get a GCWR of 52,200 lbs. by the DOT. So, you can gross ~50K legally and safely if loaded correctly. Before you get all riled up and remember this, do you know more than the DOT?

I kinda disagreed with statement. the highest GVW on a F550 is 19,500, regardless of axle weight rating combined.
7,500 + 14,700 = 22,200. If you were able to achieve those numbers, you would be overweight.

I've often pulling equipment all over the country, been thru a 100 or more DOT inspections. Every weight station wants to compare registered weight (I'm 26k on truck, 32k on trailer) then they want to see fuel and weight permits unless you have a IFTA and apportioned plate. In your home state, permits are not needed unless reentering from different state (some states require this). obviously a log book, medical card or ELD is required ( log book for part timers)

The heaviest I've been is 49K and legal.

I'll give more detail later on some unbelievable stuff when I have more time