As lead trailering engineer 
for General Motors Co., Robert Krouse knows that adding a trailer to a vehicle poses a unique set of challenges to fleet operators. He works daily to educate truck buyers on how to safely tow boats and campers, noting that the average retail customer may only tow a trailer three or four times a year.

“Training is every bit as important on the fleet side,” Krouse says. “Just as for personal use, some will drive it only a couple of times a year, some every day.”

Even the daily routine can vary on the commercial side. Loads change depending on the job, and trailers may be pulled by a number of different drivers and tow vehicles. This makes proper trailering techniques essential, even for the seasoned fleet operator.

With all that in mind, Krouse sat down with Business Fleet to discuss five common trailering mistakes and how they can be avoided.

1. Failure to calculate 
the actual weight 
of the trailer

Krouse points to landscaping trailers as a good example of how operators can misjudge the weight they’re asking their trucks to pull. The weight of the equipment inside may seem insignificant compared to the trailer itself, but it’s a principal factor in determining whether your equipment is pushing the load past your tow vehicle’s capacity.

“Retail or commercial, the same principles apply,” Krouse says. “The ratings are based on weight, and that’s what we go by.”

It’s crucial to weigh your loaded trailer at the nearest available scale before towing it. Also check to be sure the trailer’s tongue weight — the downward force exerted by the trailer’s “tongue” — is within your hitch’s rating.

2. Failure to account 
for the actual capacity of the tow vehicle

Now that you know how much weight 
you’re pulling, you just have to check that against your vehicle’s trailer weight rating (TWR), right? Not so fast, Krouse says. Pulling your truck’s rating from the Web might not provide the right number. Many manufacturers only provide each vehicle’s maximum TWR, which may depend on a particular engine or nonstandard equipment.

Your dealer or factory rep should be able to provide your vehicle’s TWR and information on how to upgrade it. Once you have the right number, be sure to add the weight of your truck — including people in the cabin and equipment in the bed — to the weight of the loaded trailer. If that figure surpasses the vehicle’s gross combination weight rating (GCWR), you’re past the point of a safe tow.

3. Overloading the trailer or tow vehicle

Failing to determine TWR and GCWR are the most common weight-rating pitfalls, but there are several other factors to consider. Krouse says that tow vehicle and trailer gross vehicle weight ratings (GVWRs), individual tow vehicle and trailer gross axle weight ratings (GAWRs) and individual tire ratings are just as important.

There’s also the trailer tongue weight, which can differ from your hitch’s rating. Failing to note any of the factors listed earlier can result in damage to the tow vehicle or trailer, not to mention excessive wear on your brakes or tires.

4. Improper setup

Now that your tow vehicle, trailer and combination weights and ratings are within range, the next objective is a proper coupling. If your hitch ball sits too high or low or your sway controls and weight-distributing spring bars are improperly adjusted, you still run the risk of damage somewhere along the setup.

To be sure the trailer load is properly balanced, for a weight-distributing hitch setup, Krouse suggests measuring the space between the top of the tow vehicle’s front tire and the bottom of the fender. That space will increase once the trailer is coupled; adjust the spring bars to get back to the initial measurement without decreasing it.

Each state sets its own standards for trailer brakes, but Krouse recommends adding a brake controller whenever you’re pulling 2,000 lbs. or more. In an electric system, a signal is sent to the trailer brakes when the tow vehicle’s brakes are applied, engaging them in unison. Several manufacturers, GM included, now offer a factory-equipped brake controller on most models.

Another option is a hydraulic brake controller, also known as a surge brake. Surge brakes employ a self-contained apparatus in the hitch that engages the trailer brakes when the tow vehicle slows down.

5. Improper road protocol

Krouse sums up his advice for driving while trailering in one word: practice.

“The operator always has to realize, it’s not like driving the tow vehicle by itself,” he says. “Don’t ever let that become back-of-mind.”

Turning, stopping, backing up, merging and changing lanes all require more time and space. There’s no substitute for practicing those maneuvers in an open area before hitting the road, and remember to 
adjust your mirrors to the length of the trailer. GM and other manufacturers offer extendable side mirrors as a factory option.

Finally, special attention must be paid to maintenance when your pickup is pulling heavy loads. Krouse lists fluids, tires and brakes as particular areas of concern. The trailer’s own brakes and tires also should be checked frequently, and trailers that sit idle for long periods should be inspected before they go back on the road.