The last hay bale has been loaded up and the sun is setting on a farm in Montana. The truck driver snorts and spits onto the ground before reaching for a set of straps and hopping onto the trailer to secure the cargo. He gets back into the cabin, starts the truck, drops it into drive, and looks to his right to see a pair of children standing a few feet away, gawking at the sight of this flatbed trailer-pickup combo stretching over 50 feet in length.

The driver smirks and waves at the kids, turning his gaze to the front and pulling away, easy on the throttle and sure of the steering. The motor hums gruffly as it returns to the dirt road, and the kids head for home, thinking all the while of the truck and what it did.

Maybe that’s the way some of us start our love of diesels, or maybe it’s some other scenario. No matter our beginnings, the pure utilitarian attitude of a diesel is something that a gasoline-driven vehicle can never attain. And, until the day pure electric motors come into fashion, it’s a diesel we will rely on when a job needs doing. It’s all about torque, period. And torque is the name of the game when it comes to one of the main draws of diesels: towing.

What are the essentials to enhance the towing capabilities of a diesel? That is the question we will answer here, as we narrow down the five top modifications that make hauling more practical, painless, and perfect.

Suspension

Since earthbound vehicles have to deal with the nasty principles of gravity and weight, one of the first things that requires upgrading for serious towing is the suspension. Two routes exist to help balance out a truck’s suspension: helper springs and airbags.

Helper springs are designed to increase the load capacity of a truck and help level out a loaded-down truck. Companies like Hellwig offer these springs in a capacity range of 500 to 3,500 pounds, and come in either constant or progressive rate models. Constant rate springs, as the name describes, provide a constant weight capacity, whereas progressive rate springs can adjust to accommodate the load placed on them.

Airbags, meanwhile, offer some of the traits of a progressive rate spring in that they are adjustable to match a load weight. This is done by increasing or decreasing air pressure, which can be performed either while stationary or on-the-go, depending on the make and model. On top of these are automatic airbag systems, which change air pressure independently of supervision to maintain ride heights regardless of payload. Companies like Air Lift, Hellwig, and Pacbrake build systems for this exact purpose.

In terms of advantages and disadvantages, airbags are beneficial when it comes to hauling uneven loads, as they can be tuned to provide one side with an unequal amount of air pressure and level out the truck. They also range in capacity from 1,000 to 5,000 pounds, making them more useful for heavy-duty scenarios than progressive rate springs.

Helper springs, on the other hand, tend to be easier to install because they do not require air lines to be routed or electronics to be wired up. They’re also better for off-road situations, where rocks, sticks, and other obstacles won’t cause damage as easily.

Towing Types

Towing a given load of cargo from Point A to Point B can be accomplished in a number of ways. For a number of users, the typical tag-style hitch receiver is a fine choice to haul around small trailers like dollies or short enclosed units, and ratings of Class 1 to Class 5 offer a great range to choose from. Nevertheless, heavier loads, like enclosed trailers and flatbeds require upgrades, and for that we have gooseneck and fifth-wheel arrangements.

A gooseneck hitch places the mounting point of a trailer inside a truck bed and uses a standard trailer ball like you’d find on a tag-style hitch. By placing the weight of a trailer over the center of the rear axle, (instead of just on an extension of the frame), a gooseneck hitch will be able to handle a great deal more than a tag-style hitch. They also offer a higher turning radius, since the pivot point is more forward and more in-line with the truck (the same goes for a fifth-wheel hitch).

A fifth-wheel hitch follows a similar makeup to a gooseneck hitch in terms of capability, but differs in characteristics. Gone is the towing ball, and in its place is horseshoe-shaped fitting that attaches the trailer to the truck. Fans of fifth-wheel hitches like them for their stability and ease of maneuverability, and the pivoting design of fifth-wheels makes them great for a smoother driving experience. As far as disadvantages go, fifth-wheels will obviously cut down on bed space, so that should be taken into account before installation. For any inquiries regarding gooseneck or fifth-wheel systems, we recommend consulting with a trusted company in the industry like B&W Trailer Hitches. 

Tuning

The common notion of tuning is that it “unlocks” power hidden inside the engine. This is because from the factory, automakers will have the engine detuned by way of the ECU to make it more optimal for everyday use, cut down on excess wear and tear, and reduce emissions. But hidden in the depths of circuitry and wiring, there lies the potential for more horsepower and torque, and tuning provides a way to access more potential. Popular terms for tuning include “programmers” and “modules,” but they mean something different.

Programmers go into the OBD-II port and reprogram the ECU using either model-specific or preprogrammed tunes, and can only be used when the truck is stopped, turned off, and able to rest for a few minutes as the reprogramming goes into effect. Custom tunes are also available for programmers, but we recommend going to a professional first.

Lastly, modules (also known as boxes) are often installed under the hood and work with the stock sensors and ECU. They can be used on-the-fly and can also display data like boost pressure, exhaust gas temperature, and more on in-cab LCD or color touchscreens.

For relatively little effort, tuning is a feasible way to squeeze upwards of 100 horsepower and 200 lb-ft of torque from the stock engine. Installation tends to be pretty simple, and the companies that make tuners have a great deal of expertise and advice to offer shops and end users. The downsides occur when you consider that auto-makers can potentially void the warranty of a truck using a tuner, and also that exhaust systems can suffer from excess temperatures, leading to premature failure. But for the ability to add an extra layer of user control and boosted power and torque, tuners demonstrate that great things can indeed come in small packages. For more info on these you can check out Edge Products, SCT, Bully Dog, Superchips, and EFI Live. 

Tires

Take a look on the Internet one day and see just how many tire companies you come across: Mickey Thompson, Toyo, Falken, and so on and so forth. The sheer multitude of tire options out there can certainly make your head spin, but where tires factor into this discussion are when we’re talking load ratings.

Seeing as towing adds an extreme amount of weight to a vehicle, tires are one aspect that become a point of concern. The more weight is placed on them, the more stress is put on the rubber, which can lead to a high amount of wear and tear and result in a popped bead, cracking, and other damaging effects. That’s why, when looking at tires, it’s important to consider the load rating.

Load ratings are determined by the Tire and Rim Association, which was established in 1903 to standardize everything relating to tires. The group has its load range chart, ascribing alphabet letters to tire ply counts in the sidewall. For example, an “A” tire has two plies, a “B” tire has four plies, a “C” tire has six plies, and so on up until the maximum “N” tire, which has 24 plies (which are not available as light truck tires, mind you). While plies definitely add durability, they also add rigidity to a tire. Thus, a higher-ply tire will be more comfortable to drive when towing versus when unloaded.

Accessories

Accessories: When a diesel rig needs icing on the towing cake, there are a number of devices and tools worth checking out to make towing more convenient, practical, and secure.

Extra lighting is one such add-on that makes a big difference down the road. Halogen lights are the old stand-by of the industry, a real tried-and-true lighting element that has been around for decades. They’re relatively inexpensive to replace and live long lives before giving up. They’re also inefficient, since their composition (iodine or bromine gas with an electrified tungsten filament) gives off a great deal of heat while radiating light, and touching them with bare hands has a tendency to cause the glass bulb to melt and lead to an explosion.

LED (light-emitting diode) lights, on the other hand, have caught up in recent years and proven to be a highly dependable choice. LEDs emit light by the movement of electrons through a semiconducting material (aluminum-gallium-arsenide, or AlGaAs, is most common), and can last thousands of hours longer than a halogen light thanks to the energy efficiency. On the downside, they produce lots of heat at the base of the diode, which can harm wiring, and are more expensive to produce than a halogen lamp. See more on lights by perusing the catalogs of Rigid Industries, KC HiLiTES, Baja Designs, Hella, and others.

Other accessories to consider are door alarms. These are actually for trailers, and can come with shock sensors to detect movement in addition to a blaring siren. They can also trigger the trailer’s brakes and set off flashing lights to boot, so any attempt to haul away the trailer will result in a screeching, screaming, and brightly lit unit, making for a very noticeable snatch-and-grab.

Up next are trailer brake controllers. These devices detect when the truck’s brakes are used, and correspond by activating the trailer’s brakes to help slow down safely. They come in two types: proportional and time-delayed. Proportional models match the intensity of the truck’s braking force in real time, where time-delayed models need an input from the user to determine their intensity and rate of application.

Last but not least, a backup camera is an absolute must these days. Small digital cameras are typically mounted into the tailgate of a truck, but that doesn’t go far enough in a towing situation. Luckily, there exist small digital cameras that can be mounted to the trailer on whatever angle the installer chooses. These go a long way toward enhancing situational awareness, whether backing out of a driveway or changing lanes on the freeway.

We hope this guide has given you a sense of the important modifications that make towing safe, fun, and practical. Sooner or later, we all must transport cargo from one area to another, and getting there in one piece is now more attainable than ever thanks to the breadth of aftermarket support and innovative inventions.