Fully loaded pickup - @ payload rating

[ABN_CBT_ENGR]

You make it sound as if it wasn't cast in concrete... and if I go 3 pounds over, that I won't die in a fiery crash. This would not go well on an RV board.

It does apparently have a wide built in margin for safety because of laws and insurance limitations.

I do have direct experience on towing calculations due to DOD work with up armored Hummers back from over there.

The end result of the towing has more to do with the rigidity of the frame ( under stress) combined with the aspect ratio of the tire footprint and towing vehicle geometry relative to wind loading of the object being towed. ( that too is considered IP because the vehicle OEM has no clue what the aerodynamics and relative speed you may be driving at so they cannot effectively calculate it)

They all usually default to the wind signature and that's the height they base the calcs on.

Hardly my wheelhouse but that's the guidance we had to go with back then.

 

[bulwnkl]

Stopping is a MUCH bigger deal, safety-wise, than pulling.

Manufacturers make judgment calls on towing limits. One manufacturer may decide that X load level will impact the vehicle such that average expected life is reduced from (their internal norm of) 150,000 miles to 120,000 miles, based on their assumption of a 20% duty cycle. Another may decide that reduction from (their internal norm of) 120,000 miles to 80,000 miles is acceptable, based on _their_ assumption of a 15% duty cycle.

I think these kinds of internal assumptions and decisions are the primary driver of the secrecy surrounding exact calculation of tow ratings.

 

[ABN_CBT_ENGR]

Manufacturers make judgment calls on towing limits. One manufacturer may decide that X load level will impact the vehicle such that average expected life is reduced from (their internal norm of) 150,000 miles to 120,000 miles, based on their assumption of a 20% duty cycle. Another may decide that reduction from (their internal norm of) 120,000 miles to 80,000 miles is acceptable, based on _their_ assumption of a 15% duty cycle.

That would be highly unlikely because nothing in engineering ( especially things that carry legal culpability) is a "judgement call".

Stopping is a critical factor in the towing equation but a secondary consideration because the actual gross load/ towing vehicle mass and contact area is easy to factor in, inertial shock is a different matter plus any additional braking from a trailer. Nobody can engineer a specification against a question mark- that's why they have a standard datum requirement to base everything against.

 

[dareo]

Nice haul. These days "fully loaded pickup" usually means an F350 Platinum with huge tires, a lift, and maybe 2 pieces of 2x4 in the bed.

 

[bulwnkl]

nothing in engineering ( especially things that carry legal culpability) is a "judgement call".

You mean like the judgment calls that lead to stuff like burning Pintos? That was a judgment call, and the court decisions around, before, and after it were judgment calls, too. Similar ones are made daily, around the world.

Nobody can engineer a specification against a question mark- that's why they have a standard datum requirement to base everything against.

The datum or requirement is the judgment call. Many things are cited so as to present the notion of concrete or somehow absolute-ness, but all of those started with a judgment call _somewhere_.

Manufacturers make judgment calls. That’s a simple, incontrovertible fact.

 

[ABN_CBT_ENGR]

You mean like the judgment calls that lead to stuff like burning Pintos? That was a judgment call, and the court decisions around, before, and after it were judgment calls, too. Similar ones are made daily, around the world.

No, those incidents are unfortunate and were done IAW with the standards of the day (Just like the Titanic had the "required" number of life boats)

Nobody considers or plans for every possible action or contingency.

The datum or requirement is the judgment call. Many things are cited so as to present the notion of concrete or somehow absolute-ness, but all of those started with a judgment call _somewhere_.

True at times but those are made by people who are not engineers so not our responsibility or liability. Remember, "engineers" NEVER said the Titanic was "unsinkable"- the business types and marketing people did.

Manufacturers make judgment calls. That’s a simple, incontrovertible fact.

There's a universal circular statement if ever there was one- that still says nothing.

How many of those projects have you engineered?

 

[bulwnkl]

You seem to have completely missed the fact that I said nothing about engineering assignments. I said that _manufacturers_ make judgment calls. The engineers work to those, but that doesn’t change the fact that they’re judgment calls.

 

[Jarlaxle]

You mean like the judgment calls that lead to stuff like burning Pintos? That was a judgment call, and the court decisions around, before, and after it were judgment calls, too. Similar ones are made daily, around the world.


The datum or requirement is the judgment call. Many things are cited so as to present the notion of concrete or somehow absolute-ness, but all of those started with a judgment call _somewhere_.

Manufacturers make judgment calls. That’s a simple, incontrovertible fact.

The only judgment call there was not building a pyre large enough for a few thousand lawyers.

 

[BeerCan]

The only judgment call there was not building a pyre large enough for a few thousand lawyers.

Until you need one, eh.

Put me in the group that went from a 150 to a super duty because of braking. The eb pulled anything I threw at it. Stopping safely was another matter.

The RV over weight police are crazy annoying but at least they get some people with less experience to think.