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Tow Ratings and the Law: Discussing the Limits of Trailer Size

The Importance of Knowing a Tow Rig’s Limitations

Bruce W. Smith
Mar 7, 2017
Photographers: Bruce W. Smith
Torque. That’s the primary driving force for our gravitation toward diesel-powered vehicles. Diesel engines are the torque kings, providing the muscle needed to move heavy loads up steep grades or through the worst conditions with relative ease compared to their gasoline counterparts. We love our oil-burners because they can haul or tow whatever we put in the bed or drop on the hitch.
That power is a huge source of pride among diesel pickup owners. It’s also a key marketing tool for the manufacturers that build our rigs. The companies flaunt tow ratings and payload capacities like world-championship titles. It’s been that way forever—big torque numbers and capacities sell trucks. The alpha dog leads the pack, right? You bet.
The downside to all the pride and hype over such numbers is the fact that when it comes to towing, they bust the door to buyers’ misinterpretation and misuse wide open. That, in turn, leads to putting truck owners at risk from safety, legal, and financial standpoints, especially when the trailer they are towing is “too big” for the rig pulling it.
Photo 2/7   |   Towing trailers of all types is a big part of owning a diesel-powered pickup and being active in the diesel hobby. Every midsize and fullsize pickup has multiple tow ratings, depending on how each is set up.
Some diesel owners might say, “Too big? Never.” If you are thinking your diesel pickup can tow anything you slap on the hitch or lock into the gooseneck or fifth-wheel, answer this simple question: What is your rig’s conventional tow rating? If you can’t answer that, those safety and financial issues should be of real concern.

Multiple Tow Ratings

Just because a vehicle has a hitch doesn’t mean it can tow whatever is attached to the ball, regardless of how monstrous the stock or modified engine’s torque and horsepower numbers are. The same applies to towing with a gooseneck or fifth-wheel setup. Every vehicle that rolls off the assembly line has a towing limit, just as it has a unique VIN. Pickups actually have several tow ratings, depending on the type of hitch used to pull the trailered load: conventional tow rating and fifth-wheel/gooseneck rating.
Those different tow ratings carry a lot of weight, both literally and legally, and they shouldn’t be taken lightly or ignored. Think of tow ratings like speed limits: Vehicle owners don’t set them; they’re just obligated by law to abide by them.
Quite often, the conventional maximum-tow rating can actually be two different weight limits when using the stock receiver hitch: 1) weight-carrying, which means a ball and shank are used with the factory hitch; or 2) weight-distributing, which involves inserting a weight-distributing hitch into the stock receiver.
Photo 3/7   |   Towing using a receiver hitch with a ball and shank is called towing in the “weight-carrying” mode. It’s not uncommon for ¾- and 1-ton diesels to be limited to 8,500 pounds (or less) of trailered weight when using this setup.
Weight-carrying tow capacities are far less than weight-distributing, because more weight is put on the rear axle. For example, some diesel-powered ’16 Ram 1500, 2500, and 3500 trucks are limited to towing 5,000 pounds with 500 pounds of tongue weight in the conventional weight-carrying setup (per the owner’s manual). Using a weight-distributing hitch raises those towing limits by 15 to 17 percent, depending on truck configuration.
Those ratings and limitations are similar with Ford’s ’16 F-250 and 350, with the maximum weight-carrying capacity set at 8,500 pounds with 850 pounds of tongue weight, per the 2016 RV & Trailer Towing Guide. Older models of all the Big Three’s diesel trucks and Nissan’s 5.0L Cummins-powered Titan XD have similar towing restrictions and hitch requirements, and some are even limited to towing only 5,000 pounds unless a weight-distributing hitch is used.
Also, note that on newer trucks with the 2.5-inch receivers, using the 2-inch adapter sleeve significantly reduces both the weight-carrying tow limit and maximum tongue weight.

Towing and the Law

Why is it important to know the weight limits and differences when towing? Liability is one reason. Vehicle control and occupant safety are others, along with the manufacturer’s warranty.
Towing more weight than the vehicle manufacturer recommends (per the owner’s manual or manufacturer’s towing-related websites) or using the wrong type of hitch for the load being towed is considered towing with an improperly equipped vehicle.
Photo 4/7   |   Weight-distributing hitches, like this model from Husky Towing Products, allow maximum conventional towing capacity for whatever truck they are installed on. The hitches are required when trailered loads exceed a certain amount as dictated by the vehicle’s manufacturer.
Think of tow ratings like speed limits: Vehicle owners don’t set them; we’re just obligated by law to abide by them. Sure, your truck can tow a trailer at 100 mph all day. But the speed limit may be 55 mph. If you have an accident while towing at high speed, things will definitely get a bit sticky.
Causing a serious accident while towing beyond your pickup manufacturer’s requirements or limits is similar, as it opens the door for legal actions based on negligence against whoever is driving the tow vehicle. It’s not a good situation to be facing, especially if you own a business.
“If I were counseling a business owner, I would say the manufacturer's guidelines detail what the applicable standards are, and a reasonably prudent person needs to follow those standards to avoid liability,” says attorney Anthony E. McNamer of McNamer and Company in Portland, Oregon. “If you don't follow the towing guidelines clearly set forth by the manufacturer, then it’s going to be very difficult to argue you were being reasonable.”
Photo 5/7   |   The maximum towing capacity vehicle manufacturers advertise is always based on towing either a gooseneck or fifth-wheel trailer.

Being Negligent

When asked about towing liability issues, Dean Holleman, Vice President and Managing Attorney of Boyce Holleman & Associates in Gulfport, Mississippi, says, “Any person who tows a trailer would be responsible to know that the towing vehicle has certain limitations which should not be exceeded.
“If the accident is caused by the vehicle being used to tow something it was not designed to tow, this could be an act of negligence by the driver, and under the theory of negligence that person most probably would be held liable,” Dean says.
He also says that while some vehicle owners may argue the tow ratings and the proper setup of their vehicle isn’t clearly noted or easy to find, he feels “most vehicles do have proper warnings and posting of limitations of towing weight.”
When it comes to negligence or the failure of the driver’s “duty to tow only that which the vehicle is designed to tow,” Dean and other attorneys we spoke with about this issue agree: If there’s an accident and the towing vehicle isn’t properly configured for the trailered weight, the injured person or persons will probably win any ensuing lawsuit.
Business owners should also take heed of such towing issues, because just one accident could ruin a small company. “One of my main concerns is that the disregarding of vehicle manufacturers’ instructions and warnings related to towing could give an insurance company grounds for denying coverage, particularly in a commercial setting,” warns Gerry McGill, whose McGill Law Firm in Pensacola, Florida, has handled liability cases on behalf of both Ford Motor Company and General Motors.
Photo 6/7   |   Lifted trucks use drop-shank hitches, which typically have reduced trailer-towing capacity. Always read the weight limits on the hitch, with the understanding the lowest rating (hitch or truck) always takes precedence for operating in a safe and responsible manner.

The Warranty Side

Legal aspects aside, ignoring the vehicle manufacturer’s towing limits and hitch requirements can also affect the truck’s warranty and its reliability after the warranty period ends.
Pickup manufacturers take enormous amounts of time to test and evaluate how heavy a trailered load can be towed from both a handling (safety) perspective as well as mechanical, before setting load limits and hitch requirements. They look at every facet of the tow vehicle’s drivetrain, from axles and gears to brakes and transmissions, tested under the most extreme of driving conditions.
Then they test the vehicles in accordance to the specifications in SAE J2807, a comprehensive trailer-towing evaluation program to which all manufacturers now adhere, before setting tow ratings for each make/model truck.
SAE J2807 testing includes emergency lane-change and braking maneuvers that replicate situations we encounter in general towing operations. When the engineers finalize all these testing results—and the marketing, service, and legal departments get their say—the tow rating (and load capacity) numbers are published in owner’s manuals and the manufacturer’s online “towing guides.”
Heavy towing on a regular basis, particularly without the proper hitch setup, is likely to lead to premature failure of drivetrain and suspension components and can promote warranty-coverage concerns. The practice also compromises handling and performance in emergency situations.
Photo 7/7   |   Whether towing a conventional trailer (foreground) or with a fifth-wheel/gooseneck (background), be mindful of your truck’s towing limits and equipment requirements as set forth by the manufacturer. Towing without a properly equipped rig places the driver in a real liability compromise should an accident occur.

Get a Bigger Hitch

Contrary to the popular thought of most diesel-pickup owners, upgrading to a heavier-duty, higher-capacity hitch—or installing helper springs, a pintle-style hitch, or airbags—doesn’t change the vehicle’s tow ratings. Those grades are set at the factory and can’t be changed once the truck leaves the assembly line—just like the vehicle’s VIN.
Even though you feel your pickup tows a heavy trailer just fine without all the special hitch setups, it doesn’t negate the fact that braking, steering, and handling can be compromised should something—or someone—unexpectedly pop up in front of you while motoring down the road.
Here’s the bottom line: You are the owner and driver, and it’s your responsibility to be aware of what your pickup can tow safely—and in accordance to the guidelines and requirements of the manufacturer that built it.
Towing safely has nothing to do with pride or your personal experiences and observations. The manufacturer’s published tow ratings dictate towing and load-carrying limits.

Finding Tow Ratings

To find your tow vehicle’s actual tow/haul capacities and what it needs to be “properly equipped” per the manufacturer’s specifications, consult the towing/trailering section of the owner’s manual. There you’ll find the bare-bones information.
For more detailed information, you can to go to a manufacturer’s website and look for an RV or trailer-towing section that details the different gross combined weight ratings and hitch requirements. Search by year, not just make and model.
To make it easy, we’ve listed a few of those links here:
Ford: fleet.ford.com/resources/ford/general/pdf/towingguides/Ford_Linc_16RV_TTgde_r1_Oct2.pdf
Chevrolet: chevrolet.com/content/dam/Chevrolet/northamerica/usa/nscwebsite/en/Home/Vehicles/Commercial/02_PDFs/MY15-Trailering-Guide.pdf
Ram Truck: ramtrucks.com/en/towing_guide/
Nissan: owners.nissanusa.com/content/techpub/common/2016/2016-nissan-towing-guide.pdf

Sources:

Ford Motor Company
fleetford.com
General Motors
gmfleetorderguide.com
Nissan
owners.nissanusa.com
Ram Trucks
ramtrucks.com
SAE International
sae.org

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