eye opener about gvwr

[GR8ADV]

Every structural component (nuts, bolts, welds, beams, connecting rods etc etc) of anything engineered, from bridges, to chairs, and yes vehicles, is designed to withstand a particular amount of load. In fact, loading is the fundamental foundation of any design.

To exceed that maximum load condition is to toss away millions of dollars of engineering and design proven by physics to be able to withstand said loading.

 

[LRNAD90]

Yes, it's comical because it's bogus... if you thought that GVWR had anything to do with performance, safety, durability, etc...

Pretty sure it has to do with all of those. That is not to say that it isn't artificially lowered to fit other parameters, but pretty sure there is significant engineering that goes into calculating the GVWR of a vehicle..

That being said, I'm sure there is significant safety margins built in as well, but pretty sure the number is not just something pulled out of some's backside.

There are certainly plenty of examples of what can happen when ignoring manufacturer's parameters..

Broken Ram 3500 Dually Shows a Camper Can Still Overload a Big Truck

This Ram 3500 is awaiting a $17,000 repair job after an enormous slide-in camper snapped its frame.

www.thedrive.com

 

[Gravelette]

Logically, it doesn't make sense to ignore GVWR just because the CGAWR is higher. Reducing it to absurdity, you might as well ignore all other limits because your tires are rated for a higher load. Not saying anyone will be killed, but it's the kind of thinking people fall into when they want to justify something that isn't "right."

 

[dstefan]

Logically, it doesn't make sense to ignore GVWR just because the CGAWR is higher. Reducing it to absurdity, you might as well ignore all other limits because your tires are rated for a higher load. Not saying anyone will be killed, but it's the kind of thinking people fall into when they want to justify something that isn't "right."

Agreed. I’m not saying we should ignore GVWR, but I am saying that depending on the truck and how it’s set up and driven that GVWR is a pretty squishy metric that is shamelessly manipulated by the OEMs. For example, my SR5 Off road Tundra has a payload that’s rated at 1350. My previous ’09 SR5 Offroad Tacoma was rated at 1250. Virtually identical stock features. There is no universe in which that makes any logical sense. Every component of the Tundra is stronger, down to the 3/4 ton 10.5” commercial Hino truck axles they use vs the weak sauce 8” rear axles in the Tacoma that were a known problem.

I’m mindful of my weight and work to keep it down, but I also know that GVWR as stated on the door placard is based specifically on the tires (as well as a lot of other stuff not mentioned I’m sure). I have seen one Toyota engineer weigh on this on Tundras.com and state that there’s a big safety margin designed in. Can’t speak to RAM or others though. In my case I have no qualms about being halfway between the GVWR and the CGAWR. The OP and others may have different circumstances. All I’m saying is know your truck, know your weight and driving style and use case and know what components you have or need to change and determine for yourself.

 

[Gravelette]

Actually, that they have similar payloads is not unreasonable or illogical. The Tundra has a higher GVWR but it also weighs more. You could probably load a Tundra to the point it would have less payload than some Tacomas. No problem, we all roll the dice when it suits us.

 

[rruff]

In fact, loading is the fundamental foundation of any design.

And where vehicles are concerned it's a big unknown and highly variable depending on the driver and where they are driving. It's not like a bridge where you know the forces it will be subject to. Lawsuits and warranty claims are the main things determining design and limits. Lawyers and bean counters have determined an "optimal" failure rate. Too few failures means it could have been made lighter and cheaper. Too many and it gets costly and the rep suffers.

I'm not saying that trucks aren't thoroughly modeled, tested, and engineered, but weight is a relatively small part of the factors that would cause failure... and even less so, when the weight you are adding actually improves the ability of the truck to handle weight.

I don’t worry about the GVWR overage. I am very focused on staying under the CGAWR, however.

You probably know this, but the axle rating isn't based on axle itself. At least not necessarily. It's an easier target to shoot for, though.

One advantage to the 2nd gen Tundra chassis staying the same for so long is that if you buy later in the cycle you have long term data on the successes and failures of others to draw on. It had by far the best reliability of any fullsize, and was very frequently heavily loaded and thrashed offroad. Even though I'm surely over GVWR, it seemed more risky to buy a domestic 3/4 ton...

 

[GR8ADV]

And where vehicles are concerned it's a big unknown and highly variable depending on the driver and where they are driving. It's not like a bridge where you know the forces it will be subject to.

Not to be rude but that is naive, to be kind.

You really think engineers cannot possibly know what loading vehicles see? And back to bridges, oh it’s not that simple either. How big a vehicle are we designing for? Are they driving fast? Are they driving slow? Will they bounce and have impact loads? Do they have 2 axels or 8? It ALL makes a difference and it is all accounted for. Do you think they just ‘winged’ a bridge capacity sign based on some lawyer in Texas??

And same with those pesky airplanes. No way they can really know what’s happening there in the sky right? Let’s just throw some rivets on there in case Billy Bob from Oklahoma sues us.

For everything built with structural integrity the loading is calculated, (both static and dynamic) with reasonable/legal/well established safety factors applied to that loading for, well, safety. The members and joints are designed accordingly.

The legal ramifications will fall back on these design elements and practices.

Planes, trains and automobiles, buildings, bridges, bicycles (you get the point) all follow the same well established practice of science. (Sorry to being that 4 letter word up as I know some of you don’t believe in it). 😂

 

[rruff]

You really think engineers cannot possibly know what loading vehicles see?

Everything from grandma only driving 1 block to church on Sundays, to Bubba getting wasted and bombing across ditches at full throttle. How much weight can each of these carry without over stressing the vehicle?

I'm an engineer, BTW.

 

[GR8ADV]

Everything from grandma only driving 1 block to church on Sundays, to Bubba getting wasted and bombing across ditches at full throttle. How much weight can each of these carry without over stressing the vehicle?

I'm an engineer, BTW.

If this is not a rhetorical question, my answer would be that the final result of their analysis was the stated GVW.

I am not sure what their driving criteria would be, but I do suspect it would mimic a reasonable use of the vehicle. A Camry for example would be expected to do different things than an f250.

 

[texasnielsen]

Not to be rude but that is naive, to be kind.

You really think engineers cannot possibly know what loading vehicles see? And back to bridges, oh it’s not that simple either. How big a vehicle are we designing for? Are they driving fast? Are they driving slow? Will they bounce and have impact loads? Do they have 2 axels or 8? It ALL makes a difference and it is all accounted for. Do you think they just ‘winged’ a bridge capacity sign based on some lawyer in Texas??

And same with those pesky airplanes. No way they can really know what’s happening there in the sky right? Let’s just throw some rivets on there in case Billy Bob from Oklahoma sues us.

For everything built with structural integrity the loading is calculated, (both static and dynamic) with reasonable/legal/well established safety factors applied to that loading for, well, safety. The members and joints are designed accordingly.

The legal ramifications will fall back on these design elements and practices.

Planes, trains and automobiles, buildings, bridges, bicycles (you get the point) all follow the same well established practice of science. (Sorry to being that 4 letter word up as I know some of you don’t believe in it). 😂

Very, very accurate sir (I can speak from the aviation side). Sadly, a particular self-identified savant believed he knew better than what established science said about carbon fiber loading and stress and convinced more than one wealthy person to part with their money to see the bottom of the ocean. That it actually succeeded once was a miracle. Several times was lunacy. The last time, obviously exceeded “his” GVWR.
Not to make light of the tragedy, with the point being that just because one may not know the science and physics behind all manner of design and construction, it doesn’t mean the knowledge doesn’t exist somewhere. Plenty of examples around the world of all manner of design (DIY or professionals) that failed due to ignorance. Ignorance being the lack of certain knowledge (not suggesting it’s a bad thing). Stupidity being aware of the knowledge but doing the opposite, etc. anyway. Gets people killed in all manner of ways.

 

[SimplyAnAdventure]

You got the Logiq dual bag set up? They are more expensive than my Alcans! I didn't even consider them given my experience with Ride Rites and Daystar cradles. Sounds like Logiq are a solid improvement.

Yes, I had RideRites and Daystar previously and these are night and day difference. I think i have $1800 into them plus $400 to install (I did the compressor and wiring, but paid a shop to pull the overloads and install the bags and air lines). If my stock springs wear out I’ll swap them out but the ability to raise and lower the truck and tilt it left to right as amazing. I can park, level and pop the electronic top on my Supertramp and be camping in well under two mins. It’s about as efficient as possible.

 

[TonyCatmandu]

Going back to "eye opener about GVWR" is why you see the truck camper world moving towards the larger base vehicles. People started getting actual weights and realized they were pushing it. It is also why you see the general trend in the industry to have 3/4 ton and 1-ton fully fitted overland trucks direct from the factory. They are replacing smaller Jeeps, SUV's and 1/2 tons.

I am not an engineer but I understand what the folks on here are trying to say with respect to vehicles being designed and engineered based on available science combined with industry best practices. I still believe that for a mass produced product being sold to the general public, there is a wide margin of error and acceptable use.

Given that the OP is not in a position to sell the house and go buy a fully tricked F550, I would say that YES, many rigs are at or over GVWR. I would also suggest that adding a bumper, winch and sliders is within the reasonable margin of error regarding GVWR for their truck. I am not an engineer, attorney or in charge of setting vehicle safty standards so take my opinion with a grain of salt for the 2 cents it is worth.

 

[Gravelette]

^^^It's fine, all we have here is opinions.

 

[Fenderfour]

At the risk of jumping in a fire...

GVWR and other things like max loads for aircraft aren't pure engineering. Sure, they start with pure engineering, analysis, testing, etc... and then other systems get thrown in like loading capacities for airports, and capacities for ground handling equipment, etc... These larger engineering systems become the basis for max loads. Then there are political systems, regulators, insurers, sales people, etc... Then there is the human factor, which would be to underrate the max load knowing that the operators/owners will overload.

So is GVWR an absolute? probably not, but you should understand the engineering systems in play before you decide to exceed them, and also be prepared for increased liability if something goes wrong.

In my experience, people online don't want data and facts and analysis, they just want to be agreed with, so I'll close with "GVWR is meaningless"

 

[Wildcat]

thanks for all the info. learned alot. after i put said gear on the truck, i will get it re-weighed. the wife and i may have to go on a diet