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Is Gross Vehicle Weight Rating . . . Overrated?
Sunday, January 8, 2012 at 3:57PM ;)
We all know most of America is overweight these days. But 2,000 pounds overweight?
Scott Lesak wrote us regarding his 1997 Mitsubishi Montero (the one in front here), which he has outfitted extensively for overland travel (his brother Mark owns the one following). Recently, Scott weighed virtually every piece of gear that goes into the Montero for a typical camping trip, and after adding in the curb weight of the vehicle, plus occupants, was concerned, if not really surprised, to find the total nearly 2,000 pounds higher than the factory’s listed 5,700-pound GVWR (Gross Vehicle Weight Rating includes empty vehicle weight plus all fluids, occupants, and cargo). He wondered if by carrying that much excess weight he was, a) risking damage to the vehicle, and, b) compromising safety on the road through reduced braking performance, etc.
To which, of course, the short answer is yes and yes.
If you’ve never weighed your own vehicle completely kitted and fitted for an overlanding trip, you might wonder how anyone could wind up a ton over the maximum recommended weight for a sturdy 4WD vehicle such as a second-generation Montero (which has a 1,300-pound cargo capacity including occupants). Trust me, it’s not that difficult. In many cases, the weight of just the modifications we bolt to our vehicles can come perilously close to topping the GVWR, before a single down sleeping bag gets tossed in the back. Look at Scott’s list of his own modifications:
150 lbs for upgrade to 35-inch tires
150 lbs for (empty) Garvin 84-inch roof rack
300 lbs for ARB bumper and 12,000-lb MM winch
200 lbs for custom rear bumper and swing-out mount
100 lbs for custom skids under transmission & transfer case
60 lbs for 15-gallon (empty) auxiliary fuel tank
100 lbs for rock sliders
80 lbs for extra AGM battery (105 amp hour; big and heavy for a 2nd battery)
100 lbs for custom drawer system (empty)
20 lbs for ExtremeAir compressor
50 lbs for fridge slide
80 lbs for Engel 60 freezer fridge (empty)
45 lbs for cargo barrier
25 lbs for 84-inch roll out awning
35 lbs for Hi-Lift Extreme jack
Remember that 1,300 pound cargo rating for the Montero? Scott just blew past that by almost 200 pounds—and he hasn’t loaded a single item of camping gear. Or fuel. Or himself. Let’s look at the rest of his list.
200 lbs for 25 gallons non-potable water for showering/cleaning
80 lbs for two 5-gallon jerry cans of potable water
92 lbs for 15 gallons fuel in auxiliary fuel tank
123 lbs for fuel in main tank
60 lbs clothing for 4 persons for 5 days
30 lbs for storage box #1 containing propane grill/heater and various accessories
40 lbs for storage box #2 containing cookware, electric coffee pot, dry food items
40 lbs for 4 sleeping bags, towels, pillows
20 lbs for 4 folding chairs
20 lbs for tent/awning mosquito net/folding table
20 lbs for firewood
10 lbs for propane tank
5 lbs for axe/sledge
700 lbs for passengers
40 lbs for hiking pack
60 lbs for gear in drawer (hoses for shower system, chains, recovery straps, 1 qt engine oil, 1 qt trans fluid, Hi-Lift attachments, basic tools, air hoses for tires/air mattress, lantern, fire ring, 1200 watt inverter)
20 lbs food/drink in the fridge
10 lbs cold weather clothing/rain gear suits
That’s another 1,570 pounds of people and stuff. And while it’s certainly comprehensive, there’s nothing in the entire list that’s really out of the ordinary for a vehicle set up for backroad exploration and camping with a family in mind. But what about unforeseen consequences from all that weight?
Every vehicle has a GVWR, or Gross Vehicle Weight Rating, specified by the manufacturer. The information is usually on a sticker on the edge of the driver’s door or door frame, as well as in the owner’s manual. There are dozens of factors that can be used to calculate GVWR, which isn’t to say that all manufacturers use the same list. Most obvious is the suspension, including spring rates, shock valving, anti-roll bars, etc. Braking capacity is another critical variable. Chassis design, wheel and tire size and rating, engine horsepower and torque, transmission capacity, differential gear size and ratio, driveshafts, axles, wheel bearings, CV joints—all these and more contribute in some way to the vehicle’s capacity to haul a load. Whether or not they’re all included by the manufacturer, they should be considered as an interdependent system by the owner.
You might think fear of litigation would drive manufacturers to be conservative regarding GVWR, but, particularly when discussing pickup trucks, advertising trumps reality. If your pickup has an 8,000-pound GVWR, and the brand across the street boasts a 8,500-pound GVWR, that makes your truck look puny in the one-upmanship game with which the American truck market is obsessed. So just because your vehicle is rated to carry 2,000 pounds of cargo doesn’t mean it can do it comfortably—or even safely. As an example, our 2000 Toyota Tacoma Extra Cab with the TRD package was rated to carry 1,400 pounds, if memory serves. Yet with nothing but a 700-pound Four Wheel Camper in the bed the rear end sagged alarmingly, the headlights lit up bedrooms in third-floor apartments, and we negotiated corners looking like a sailboat rounding a leeward buoy. Immediate suspension modification was called for. In our case, a set of heavy-duty shock absorbers and a pair of adjustable air bags handled the situation perfectly.
Scott’s Montero is equipped with a set of custom coil springs, and from photographs they appear to handle the extra load very well. The factory shocks that came on the vehicle are adjustable, and now live permanently in the “firm” mode (brother Mark’s Montero didn’t have that option and rides on Old Man Emu shocks).
Scott also extensively modified the vehicle for better performance on challenging trails. The tires are 35-inch Goodyear Wranglers, significantly taller (and heavier, as noted in his list) than the stock 30-inch tires. To fit them, Scott raised the suspension two inches and installed a two-inch body lift as well. He compensated for the taller tires by changing the differential gears from 4.2/1 to 4.9/1. In addition, the modest stock transfer case ratio of 1.9:1 is now a healthy 3.15:1, giving the Montero a very good 43:1 crawl ratio in 1st/low. The vehicle also has a stock Mitsubishi rear diff lock and an ARB front locker.
On Class 3 and 4 trails, there’s very little doubt Scott’s Montero would outperform a stock one. But how do his modifications, combined with the oversized load, affect its durability and safety as an overland vehicle?
The springs are clearly doing their job keeping the vehicle level and retaining sufficient suspension travel. The next component to consider is the braking system. Scott is lucky in that his Montero came with four-wheel disc brakes, not very common on mid-90s SUVs. Nevertheless, at nearly a ton over GVWR those discs are obviously working harder than they would be in a lightly loaded truck, and there’s no need for a track test to confidently assume emergency stopping distances are increased. And the bigger tires don’t help at all, as they add an enormous amount of rotating mass. I have a study in hand from the American Association of Motor Vehicle Administrators, in which they tested braking effectiveness with successively larger tires on a 1992 F150 Ford standard-cab pickup, in terms of the g-force generated by specific pressure on the brake pedal. For example, 76 pounds of pedal pressure—equivalent to a hard stop—produced .57g of retardation with 32-inch tires, but only .51g with 35-inch tires. With 150 pounds of pedal pressure—a full panic stop—they recorded .68g with the 32-inch tires, and only .62g with 35-inch tires. Since Scott’s Montero’s stock tires were 30-inchers, we might expect the difference to be larger in his case. In addition, the weight of the roof rack and its contents puts more stress on the front brakes in a panic stop, and will kick in the Montero’s rear anti-lock system earlier.
Those larger tires, combined with the suspension and body lift and the loaded roof rack, also negatively affect the center of gravity of the vehicle. In the same study referenced above, the Ford truck was evaluated for Static Stability Factor (SSF), an industry standard for determining the vehicle’s chances of rolling during a violent emergency maneuver. On stock 29-inch tires with no suspension modifications, the chances of rolling were calculated at 10 to 20 percent—low enough to earn the truck a four-star rating (out of a possible five). On 35-inch tires, with a three-inch body lift and a four-inch suspension lift—not at all out of the ordinary on a full-size truck—the chances of rolling went up to 30 to 40 percent, enough to drop it to a two-star rating. And that’s without a loaded roof rack. (I doubt any of this is a revelation to Scott, but I found it interesting to see actual figures attached to what we know instinctively.)
I got a dramatic seat-of-the-pants lesson in the effect a loaded roof rack can have on a trip to Mexico in my FJ40 (with its short 90-inch wheelbase and tall profile), when I rashly decided to carry an uninflated 14-foot Zodiac and a 40-horsepower Yamaha outboard up top. Total weight, including the massive Con-Ferr rack, about 600 pounds. All went reasonably well on the curvy road to Hermosillo—until I had to dodge a cow that stepped into my lane: Oh. ooh. C’mon. Jeeeez.
Back on four wheels, I thought calmly to myself, Right. Last trip with a powerboat on the roof.
Looking at the rest of Scott’s modifications, the 4.9 ring and pinion gears he installed are weaker than the stock 4.2 gears, due to the smaller pinion needed to achieve the higher ratio. Combined with the 35-inch tires this compromises the drivetrain strength. However, the second-generation Monteros came with mighty 9.5-inch rear ring gears, and substantial 8-inch gears in the front (independent) diff. So I suspect this won’t be the problem it is for those kids who stick 42-inch Mudders on Toyota pickups with 7.5-inch front diffs, then punch the locker when one wheel is spinning in thin air.
On the other side of the coin, the lower crawl ratio in the Montero is a definite asset, since it allows Scott to tackle rough sections at lower speeds, reducing the possibility of drivetrain stress, enhancing engine braking on descents, and easing transitions into off-camber situations with that higher CG. Of course high range isn’t negatively affected, so road performance remains normal—although I’d bet the combination of weight, windage, lift, and tires on Scott’s vehicle drops fuel economy of the V6 into the low teens more often than he’d like.
The last concern for Scott would be stress on the Montero’s bodywork and chassis. Again, he’s fortunate to have a strong, fully boxed ladder frame with no known weak points. The front double-wishbone and multilink rear suspension structure is sturdy and easy to modify for increased capacity. The roof rack mounting points on the drip rails might be a concern, but frequent inspection should be sufficient to detect any incipient issues.
What do the lessons from Scott Lesak’s thoughtfully outfitted, but overloaded, Montero tell the rest of us?
First, most obviously, is that if possible one should keep the all-up weight of the vehicle below the manufacturer’s GVWR. It’s easy to add a set of heavy-duty springs or air bags and then just start throwing stuff in, but just because the truck sits level doesn’t mean it isn’t dangerously overloaded. Scott showed a great deal of thoughtfulness by calculating the total weight of his Montero; how many of us have done the same, or paid five bucks at a commercial scale to see what our fully loaded overland vehicle weighs? With solid figures in hand, it’s a lot easier to decide if action is necessary to alleviate the situation.
However, rather than assembling a completely modified vehicle and camping kit, and then finding out what it all weighs, a better and less expensive strategy would be to learn from Scott’s example, and pay attention to weight from the beginning, when first modifying the vehicle and buying camping gear.
It’s common for those starting out in the overlanding world to be tempted to get the “look” down first (I certainly was). Those winch-mounted bull bars, roof racks with six driving lights, and multi-function rear bumper/swing-outs look absolutely ace, but each one not only adds weight, it does so in the worst possible place: on the ends of the vehicle, and on top. Decide carefully whether or not you really need each. How I wish more manufacturers made sturdy winch bumpers without the bull bar, which very, very few of us really need. But apparently the market demands the full-on Aussie look . . .
Camping equipment can get out of hand easily too. Personally I think it’s odd to drive a 4,000-pound vehicle somewhere, then sleep in a five-pound mountaineering tent and cook over a microweight backpacking stove, as some friends do—but if sleeping and eating are just chores to be dealt with for you in between hikes or fishing, why carry more weight? I like to tell people to evaluate their priorities and splurge there first. For example, when car camping I like to have a tent with stand-up headroom inside, and real cots to sleep on. But I’m happy with a single-burner stove and one-pot meals. Roseann enjoys cooking, so she prefers a more comprehensive kitchen. We’ve picked and chosen to arrive at a compromise—a modest-sized but full-height tent and lightweight aluminum cots; a well-equipped kitchen mitigated by such things as a Worthington aluminum propane cylinder, which weighs half what an equivalent steel tank does. The result is a comfortable camping setup for two people (a vital distinction from Scott’s family situation). Yet, according to my calculations taking into account the known weight of our FJ60 (with M8000 winch, Slee rear bumper, and 40 gallons of diesel), with everything aboard we are just nudging past its 5,380-pound GVWR—not too bad.
When loading gear for a trip, remember that everything adds up, not just the big bulky items. Do you really need an axe, or would a hatchet or folding saw suffice? One day not long ago I finally tossed out the never-used 25-pound choker chain in our winch kit. What a difference that made. I also discovered we had somehow wound up with two folding shovels in the vehicle—not really necessary. And what on earth was that old three-D-cell Maglite still doing stuffed under the front seat? Two pounds saved . . .
If you do find yourself unavoidably abusing your vehicle’s GVWR, there are several ways to mitigate the potential side effects. First, make sure your most vital item of safety gear—the braking system—is completely up to snuff. Eschew the $49.99 lifetime brake job at the muffler shop and install the best brake pads and shoes you can find. Likewise, suspension bits should be the best available. I’ve found that, especially with shock absorbers, you really do get what you pay for. If your vehicle is equipped with anti-roll bars (a.k.a. sway bars), consider upgrading them to thicker units to reduce body roll in turns (although this will diminish compliance on trails unless you have disconnectable bars). And when on a trip, force yourself to check everything on the vehicle religiously, from the tires on up, every day—particluarly those pieces that take the most abuse from weight.
Research your vehicle to see if there are well-known weak points in its running gear or chassis. The internet has made this child’s play—you can bet if a vehicle has a common problem, word will get out. For example, a search for “Toyota Tacoma frame problems” will acquaint you with the known weakness in the rear of the frames on first-generation Tacomas. Several companies sell weld-in gussets to address the issue on this otherwise superb truck. Mid-80s Chevy trucks are notorious for numerous frame, shock-mount, and steering box weaknesses. Even Ford’s recent über-truck, the Raptor, is showing early signs of a serious chassis flaw, at least for those owners who insist on driving them like the commercials suggest. All these problems have been extensively discussed on the web.
Finally, most obviously: Pay attention to your driving, and adjust it to suit the lower capabilities of the overloaded vehicle in terms of braking performance, emergency maneuvering, side-slope security, and so on.
What would I do differently in Scott’s place? Monday-morning quarterbacking is the easiest job in the world. However, given the situation he described, I’d be very tempted to look into a 4WD-capable utility trailer from one of the growing number of companies offering them. Offsetting the hassle of a trailer would be the elimination of that 150-pound roof rack (and ladder), and the redistribution of its load, along with much more gear from the Montero’s cargo bay—which would likely mean that the 100-pound drawer system could be tossed out, along with, perhaps, the 45-pound cargo barrier. That 280 pounds of water could go in the trailer as well, as could the jerry cans which now have to reside on that 200-pound custom rear bumper and swing out. Toss that too (or go for a much lighter Hi-Lift-capable bumper with just a tire mount). With the fridge in the trailer the 50-pound fridge slide could go. We just lost over 500 pounds in one paragraph—which would, ahem, go some ways toward offsetting the weight of the trailer (although towed weight is much different from carried weight). The entire load would be distributed much more evenly (and lower), relieving the burden on the Montero. I’d be curious to see a controlled experiment regarding highway fuel economy comparing a vehicle with a high roof load to one towing a utility trailer. I strongly suspect the trailer would add more drag, but it might not be a huge difference.
On the vehicle itself, a few things jumped out at me, but again from my own perspective. The Garvin roof rack seems immensely heavy—the full-length aluminum Front Runner rack we use when necessary on our FJ60 is light enough for me to lift with one arm, yet sturdy enough to stand on. Scott’s 12,000-pound-capacity Mile Marker winch is actually well-matched to the total weight of his vehicle (gross weight x 1.5 is the general rule), but depending on frequency of use I’d be tempted to go with a Warn M8000 and synthetic line—total weight less than 80 pounds—and employ snatch blocks to increase pulling power. That would not only save weight but would remove it from the end of the vehicle, where its effects are magnified.
Scott apparently knows what he needs in the way of tires, given where he wants to go (those dual diff locks and 43:1 crawl ratio are clues). For myself, I’ve never seen a need for tires larger than 33-inch on a vehicle that size. That would eliminate the need for the body lift, thus saving rotating weight (the worst kind) and lowering the center of gravity at the same time.
In the end, while Scott is certainly stretching the load-carrying ability of his vehicle, he could have done much worse than to choose the fine second-generation Montero as his platform. Here’s hoping it and Mark’s twin hold up for many thousands of miles of family adventuring.
#overlandtech in Tech
Reader Comments (12)
Excellent article! Driving a Montero this especially caught my attention. I see so many "overloaded" vehicles that it made me rethink how I load my truck. I did away with a roof rack and utilized Thule bars to hold my Maggiolina RTT (I know its heavy). I also removed my second and third row seats, placed my Hilift and water (20 gal) in foot well of second row. My storage is all in light, quiet, RedOxx bags, retained by Raingler netting. I do have an ARB bumper, but no winch and utilize Maxtrax, front/rear lockers, hilift, straps and a good shovel for recovery. I stopped at 33" tires, no lifts, and replaced my low range with a 3.15. We pack freeze dried/dehydrated foods and utilize one 2-burner stove and mostly backpacking gear, and water filter. A Frig is on our list! Our system may not work for some, but my thinking of keeping it simple and light will help prevent problems down the road.
I really appreciated this article and now want to see what my rig weighs loaded. Hopefully others will see the logic and importance of safety first!
Thanks for this article. I would emphasize two considerations for an overloaded vehicle that the article touched on.
First, consider the carrying capacity of your tires. Be sure to check the weight carried by each axle as well as the overall vehicle weight. You can increase carrying capacity by increasing the air pressure in the tire, but only up to the manufacturer's recommended highest pressure. Since lowering tire pressure is a favorite trick to gain traction and improve comfort when driving offroad, it's vital to know your tires' carrying capacity at different inflation pressures. Information about maximum weight and tire pressure can be found on the tire manufacturer's web site.
Second, the vehicle manufacturer developed the engine cooling system with highway use in mind, not overlanding at low speed. Getting heat out of the engine compartment is more difficult when driving offroad. Adding extra weight to the vehicle makes the engine and transmission work harder. An overheated engine risks damage like blown head gasket, warped head or engine block, and weakened piston rings. An overheated automatic transmission can "burn" the transmission fluid, leading to internal damage. Keep a close eye on your temperature gauge when driving an overloaded vehicle. If the engine or transmission temp tends to run hot, consider upgrading the cooling system with a larger radiator and more powerful fan. A hood with louvers or openings to help let the hot air out is another way to improve cooling system performance at low speeds.
Best advice: Avoid overloading. Use a vehicle designed for the task at hand.
Outstanding article. You thoroughly covered every aspect of GVWR and vehicle load weight that I could think of. Maybe it's my inner list-making nerd, or my backpacking experience (where you have to carry everything on your back), but weight is always a consideration and usually a compromise.
Good article. My daily overload is a 3/4-ton pickup with a one-ton camper, then add gear and fluids and people. Also check those tire ratings. Look at an overloaded fifth-wheel and check the tire ratings and gross on it. I had a friend refuse delivery on his trailer unless they put proper capacity tires on at their expense. His experience to even check was 25 years of driving an 18 wheeler. I asked another friend who works for state DOT why don't they weigh these RVs upon entry like they do 18 wheelers. His answer was, the state would lose tourists. I drove Landcruisers for 30 years; now a Tacoma with the TRD package. Interesting how when I still backpacked I could get all I needed for a week in 50# Now I have a 2500# Casita Camper behind the truck.
Parkerdraw
Thanks for the comments, and good added advice on tire ratings and cooling systems.
Excellent article, Jonathan. Thank you. That's the first time I've seen any real data on the effects of braking after fitting larger tires.
I pay close attention to GVWR. Actually bought my current truck after realizing that my previous truck did not have enough usable payload for the way I want to travel.
Staying within GVWR is a strong point in favor of choosing a full-size pickup for an overland vehicle, at least in North America. My 2007 Dodge Power Wagon loaded with my gear and supplies for an extended back country trip is still more than 600 pounds under GVWR. And as a bonus, I didn't have to add a lot of aftermarket modifications. Most of the things folks typically add to a vehicle came on this one from the factory.
Regarding the trailer option: Another benefit to this set up is the addition of trailer brakes. Upgrading the brakes on the tow vehicle can be nearly impossible. Adding braking capacity by choosing a trailer with brakes is simple.
Being a pilot I am all to well familiar with weight. Be sure you carry what is necessary but pick the lightest product that has been tested to to fulfill your task. A sign on the inside of the hanger where the Voyager Aircraft was being built sums it up. "If you drop it and it hits the floor, its to heavy". Well perhaps not that light but you get my drift. Bill
Great article and reminder for all.
Having a similar rig (96SR Montero) with similar wheeling intentions as Scott (known him since he purchased his Montero) I too have taken GVW into consideration when deciding what I bring when wheeling. Over the years I've done what I can to minimize the extra weight when wheeling. I'm still building my current rig with a similar setup (35's, water & gas storage, etc.) and once I'm done I do intend to weigh it at a commercial scale to ensure I'm not overloaded... Oh and before I forget, kudo's to Scottie & Mark for getting featured in an article!! :D
I agree that this is an exceptionally well-done article by a man who apparently knows what he's talking about.
I'm interested in the best way of calculating cg for my three rigs and the degrees of crossfall I can safely negotiate. Back in the '70's, in my '68 Bronco, I encountered a situation in Baja where my intuition told me that I could slip and roll to oblivion, but being younger, chose to use my crosswind landing technique to get across the hard rock surface, hitting the downhill side of the “road” pointed as much uphill as possible with my speed up (no wing to put down on the uphill side, but I wished I had an outrigger I could have loaded with rocks). Ok, so now I’m a lot older, but unfortunately not wiser — yet. Still, I want to get even older.
We have a 2005 F250 diesel 6.0l HD with an Outfitter camper that we’re replacing with a 1990 Fuso FG (Diesel, dual-wheel, 12,600 GVWR) with a Callen custom camper, a pretty tall vehicle (9’ 2”), but most of the weight is fairly close to the frame. I want to KNOW when this thing is getting close to the rollover point, not guess. Any ideas?
Even though we’re going to sell the Ford/Outfitter one of these days, I would still like to (finally) calculate the cg for that too. This one has air bags and Bilstein shocks, and the Outfitter is a pop-up, so the cg is lower than most truck camper rigs, but I still want to be able to tell prospective buyers how to calculate the tipping point.
Our “town” car (my wife’s) is a 2008 Nissan Off Road model with Bilstein shocks and 6-speed manual transmission standard, and I am also interested in properly outfitting it for camping too, keeping the cg low and the load as far under GVWR as possible consistent with reasonable comfort and overall adequacy. This is the most relevant of our vehicles to your article. Here, I am interested in a true off-road trailer option, but I’m hung up on hitches. There’s an interesting trailer (I think it’s made in Azusa, CA?) that has a convertible hitch (ball to Pintel), but I’m not a big fan of the Pintel (clunky). I ran across a hitch made in Australia on the Internet some time back, but forgot the name. It looked good; something like a universal joint, that was apparently good on the highway and off-road. Anybody know about this or other hitch set-ups?
I’ll be interested in any comments on loading and modifying any of these vehicles (except the Ford, beyond the cg question). Thanks to all.
Wayne, thanks for your comments. Like you, I'd love to have an algorithm to calculate the tipping point of a vehicle. Back in the day, a very few manufacturers listed safe side-slope angles for their expedition vehicles. Land Rover claimed 45 degrees for the Series II vehicles if I recall correctly. If you've ever been in a 4WD vehicle equipped with a tilt gauge that's reading anywhere beyond 30 degrees, you know it gets intimidating quickly. Forty five would be impressive.
Of course, no one lists such things any more. Given the differences in options and aftermarket equipment between vehicles - even the same model - the only way to discover the tipping point of an individual vehicle would be to tip it until it went over. I've long pondered doing just such a test with a manufactured tilt table that would enable safe tilting with the vehicle secured. It would be interesting not only to compare different vehicles, but to determine the effects of roof racks, suspension lifts, campers, bigger tires - all sorts of variables, the ramifications of which we can now only guess at.
The problem with such a test, of course, is that it would be static. On a trail there are a hundred variables that would alter the tipping point one way or another. You could be trundling along comfortably in your F250, which tested at 40 degrees, thinking you're safe on a 35-degree slope, and then one little hole on the downhill side or one little rock on the uphill side could just nudge the whole rig to 41 degrees, and . . . bye.
Still - having a base figure would be interesting if nothing else. And it would create an entire new category of bragging rights.
Regarding the trailer hitch: Go look at the Adventure Trailers site (adventuretrailers.com). Their multi-axis coupler allows a huge range of articulation, and their trailers might be just what you're looking for.
Thanks, Jonathan. I agree with everything you've said. Yes, there's a lot of physics going on there, and I suspect that lawyers and other ribbon-clerk types would not want to hang the company's butt out to dry. That means you're on your own.
Horse pucky. We shouldn't be. The mfrs should run both static and dynamic tests as well as "real-world" tests to improve professionalism and not lead their customers astray with TV ads that demonstrate capabilities that their vehicles are "capable" of performing only when set up by stunt drivers and other kinds of fakery.
Trouble is, we are a minor market segment.
Aircraft manufacturers couldn't get certification without calculations, modeling, and testing--and setting parameters that include a fudge or "safety" factor. There are lots of ways this could be done short of the folklore, some useful, a lot not, that most people depend upon. And there are a lot of damned fools and incompetents out there who will kill themselves and others who might not even be touched by such an effort.
The worst potential "downside" of all this is that it might cause said fools to push the envelope. Nothing's perfect, and maybe teaching ourselves is the best way after all. I have driven trucks, tractors, and cars for several decades, and I can always learn more. Anybody who claims to be an "expert" is the kind of person I subject to closer scrutiny, not less. Maybe they are. But overconfidence is bad for them and bad for the rest of us--especially passengers and bystanders.
Thanks for the link.
Something no one seems to mention is insurance and liability if you exceed the manufacturers GVW , if this was shown to be a factor !!!