Automotive

We "Tow Like a Pro" in Southern Utah with GMC

We "Tow Like a Pro" in Souther...
Yes, towing the ATVs with a truck was an excuse to use said ATVs in the sand dunes of Zion Park – no, we aren't ashamed of that
Yes, towing the ATVs with a truck was an excuse to use said ATVs in the sand dunes of Zion Park – no, we aren't ashamed of that
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Coming out of Zion Canyon, we stopped at a facade town in front of a tourist trap, complete with a faux jail, a $1 petting zoo, and sarsaparilla
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Coming out of Zion Canyon, we stopped at a facade town in front of a tourist trap, complete with a faux jail, a $1 petting zoo, and sarsaparilla
The covered wagon in the background caused the author to immediately say "You have died of dysentery" 
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The covered wagon in the background caused the author to immediately say "You have died of dysentery" 
The beauty of Zion Park and Zion Canyon cannot be overstated and makes for some beautiful photo ops
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The beauty of Zion Park and Zion Canyon cannot be overstated and makes for some beautiful photo ops
Zion Canyon and Zion Park are located just east of St George, Utah in the wonders of Utah's southern desert
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Zion Canyon and Zion Park are located just east of St George, Utah in the wonders of Utah's southern desert
Inside, the 2018 GMC Sierra Denali is a well-done package of get-r-done truck design and passenger comfort
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Inside, the 2018 GMC Sierra Denali is a well-done package of get-r-done truck design and passenger comfort
Measuring the change in height of the fender edge can gauge how much weight the trailer is putting on the rear of the truck
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Measuring the change in height of the fender edge can gauge how much weight the trailer is putting on the rear of the truck
This Sierra Denali 1500 and trailer were used as our demonstration of trailering safety as GMC's crew walked us through Tow Like a Pro basics
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This Sierra Denali 1500 and trailer were used as our demonstration of trailering safety as GMC's crew walked us through Tow Like a Pro basics
Set to go, our trailer is attached to the Sierra Denali and its precious ATV cargo is secured
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Set to go, our trailer is attached to the Sierra Denali and its precious ATV cargo is secured
Our initial trailer was a "worst of" combination of two four-seat ATVs on a long car hauler and the smaller of the two engines in the Sierra Denali truck pulling it
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Our initial trailer was a "worst of" combination of two four-seat ATVs on a long car hauler and the smaller of the two engines in the Sierra Denali truck pulling it
Adjacent to our "worst of" combination of truck-trailer-load was a "best of" combination of a 6.2L-engined Sierra Denali and a trailer with a two-door and four-door ATV on board
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Adjacent to our "worst of" combination of truck-trailer-load was a "best of" combination of a 6.2L-engined Sierra Denali and a trailer with a two-door and four-door ATV on board
Our hitch setup on the GMC Sierra Denali illustrates the crossed safety chains meant to cradle the trailer tongue should it come loose
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Our hitch setup on the GMC Sierra Denali illustrates the crossed safety chains meant to cradle the trailer tongue should it come loose
The author takes a two-door ATV through the dunes, as fellow journalist James Hills snaps a photo, chanting "Go, Speed Racer!"
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The author takes a two-door ATV through the dunes, as fellow journalist James Hills snaps a photo, chanting "Go, Speed Racer!"
Zion Canyon is full of grandeur to which this photo does little justice
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Zion Canyon is full of grandeur to which this photo does little justice
The Sierra Denali 1500 with the 6.2L V8 can tow up to 12,500 pounds
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The Sierra Denali 1500 with the 6.2L V8 can tow up to 12,500 pounds
Yes, towing the ATVs with a truck was an excuse to use said ATVs in the sand dunes of Zion Park – no, we aren't ashamed of that
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Yes, towing the ATVs with a truck was an excuse to use said ATVs in the sand dunes of Zion Park – no, we aren't ashamed of that
Our guide led the group through the Coral Pink Sand Dunes area to show us where we could go
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Our guide led the group through the Coral Pink Sand Dunes area to show us where we could go
ATVs can go buck wild out on the sand in the Coral Pink Sand Dunes recreation area
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ATVs can go buck wild out on the sand in the Coral Pink Sand Dunes recreation area
The author sails down a dune headed for certain disaster when he attempts to create epic rooster tails of sand, but superior skill (luck) saves the day
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The author sails down a dune headed for certain disaster when he attempts to create epic rooster tails of sand, but superior skill (luck) saves the day
Even with its smaller V8, the 2018 GMC Sierra Denali 1500 did very well pulling a trailer up the canyon to Zion Park
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Even with its smaller V8, the 2018 GMC Sierra Denali 1500 did very well pulling a trailer up the canyon to Zion Park
The author in a four-seat ATV bounces through the sand of the Coral Pink Sand Dunes in Zion Park
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The author in a four-seat ATV bounces through the sand of the Coral Pink Sand Dunes in Zion Park
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If you look through the gallery in this article, you'll likely get the impression that we used towing with pickup trucks as an excuse to spend a day on the sand dunes in ATVs and touring Zion Park. You'd be 99 percent correct in that assumption. It turns out though, even for experts, towing is more than it appears.

We arrived in St. George, Utah and met with GMC representatives to talk about towing. After an early morning breakfast and debrief on the day's plans, we looked over the trucks and trailers and their intended cargo. The trucks were 2018 GMC Sierra Denali pickups with a 5.3-liter V8 or 6.2-liter V8 gasoline engine. The trailers were bumper-pulled, two-axle, flatbed vehicle haulers. On those trailers were two side-by-side all-terrain vehicles (ATVs) with either two or four seats, strapped down carefully to the flatbed.

We were given a crash course in towing, with the more expert of us being paired with less seasoned drivers. I personally hadn't expected to learn much at an event like this, expecting the tow portion to be fairly cut-and-dried as I've driven semi-trucks professionally and pulled trailers of all types behind vehicles of all sizes. My assumption was incorrect. Riding with someone who hasn't towed much before was an eye-opener.

The crash course from GMC included what types of trailer hitches are available on today's market, how they fit in a vehicle capability lineup, and why it's important to know the differences. A Class IV trailer hitch, for example, cannot pull the kind of load that a fifth-wheel hitch can. Further, just because a vehicle comes with a trailering setup doesn't necessarily mean it's capable of pulling the trailer you might want to pull. These things should be obvious, but many are unschooled in both the options for towing and in the weight limitations for any given towing system.

Measuring the change in height of the fender edge can gauge how much weight the trailer is putting on the rear of the truck
Measuring the change in height of the fender edge can gauge how much weight the trailer is putting on the rear of the truck

Trailer Weights and Knowing the Load

A trailer, for example, puts not only pulled weight (added vehicle weight behind) to the truck, but also adds cargo weight by pushing down on the truck's rear axle. The overall weight of the trailer and its cargo is measured versus vehicle towing capacity. Our Sierra 1500 Denali trucks, for example, have a maximum towing capacity of 9,300 lb (4,218 kg) in their lightest configuration and about 12,500 lb (5,669 kg) in their heaviest setup. Our trailers had about 6,500 lb (2,948 kg) of total weight to them (trailer and cargo).

The way weight is distributed on a trailer is very important. This is where "tongue weight" comes into play. Having 5,000 pounds of cargo, for example, is well within the parameters of the trucks we were driving, but if all of that weight is on the front of the trailer, it will have a teeter-totter (fulcrum) effect, pushing down on the "tongue" of the trailer, pressing down on the rear of the truck. That, in turn, lifts the front of the truck like a child's teeter-totter, pushing the front wheels off the ground, reducing traction and thus braking and steering control.

Optimally, the tongue weight of the trailer will be about 10-15 percent of the truck's weight. In our case, the truck itself weighed about 5,500 lb (2,495 kg) on its own. So a tongue weight of no more than 550 to 825 lb (249 to 374 kg) is optimal.

On paper, all of this sounds great, but in the real world, the logistics of measuring these weights is problematic. Most truck stops have a scale that can weigh individual axles as well as overall vehicle weight with a trailer. That's fine and dandy if those scales are readily accessible, but this is not always the case. An alternative is to make some measurements of your own.

On a level surface, measuring at the front of the pickup, without a load, from the trim (edge of the wheel well) down to the ground and then comparing that to the same measurement made with the trailer hitched up is a quick field method of adjusting tongue weights. If the measurement stays within a few millimeters and doesn't "lift" (increase) by more than a half an inch (1.3 cm), then the tongue weight is acceptable. This rule of thumb works with most pickup trucks, regardless of load carrying capacity.

Other trailering tricks include crossing the safety chains connecting the trailer to the truck so that they "cradle" the hitch itself. Thus if the trailer comes loose from the ball hitch, it will fall into that cradle rather than drag on the ground. A dragging trailer tongue can become a catapulted trailer quite easily on the highway. Testing trailer brakes (if equipped), lighting, and other items are fairly straightforward tasks, but are often overlooked trailer hookup requirements as well.

Even with its smaller V8, the 2018 GMC Sierra Denali 1500 did very well pulling a trailer up the canyon to Zion Park
Even with its smaller V8, the 2018 GMC Sierra Denali 1500 did very well pulling a trailer up the canyon to Zion Park

Towing and Engine Power

Our first tow was with the smaller-engined GMC Sierra 1500 Denali, pulling the loaded trailer out of the city of St. George and into the mountains to the east. We were headed towards Zion National Park, but driving through town to the highway took some time. In this stop-and-go situation, it was apparent that the truck's 5.3L was capable of the task, but a larger engine would have less trouble getting the load moving out of a light or up the on-ramp to the interstate.

In these situations, it is obvious why having more than enough to do the job is often confidence-building when towing. Once we stopped for a break and swapped drivers, my drive partner, Eric, helped establish this as he somewhat nervously took the wheel to continue our trip. I also began to learn that there is more to towing than I remember having to learn – largely because most of it comes naturally once it's been done regularly.

Turning corners when towing a trailer, for example, means watching where the trailer's axles will end up as you turn. The track for the trailer's tires versus the truck will vary depending on the length of the trailer, specifically the distance from the rear axle of the truck and the axles on the trailer. I showed Eric how to "button hook" a turn, leading the truck's nose straight into an intersection and turning at the last minute, rather than making the natural curve most car drivers tend towards. This maneuver pulls the trailer forward before turning it, shortening the trailer's track so the wheels don't smack into a curb or vehicle. This is best done slowly, which might make drivers behind unhappy with the time being taken, but it keeps trailer loads from shifting and mistakes from becoming disasters.

From there, a light foot on the throttle and brakes is key. Adding plenty of following distance to give room for stopping finishes the basic requirements for trailering. Then, in our case, having a navigator who can read the whole map and directions without getting distracted is also key. Which means I shouldn't be navigating because I'm terrible at it.

The author sails down a dune headed for certain disaster when he attempts to create epic rooster tails of sand, but superior skill (luck) saves the day
The author sails down a dune headed for certain disaster when he attempts to create epic rooster tails of sand, but superior skill (luck) saves the day

Fun times on the dunes

Once we arrived at the Coral Pink Sand Dunes in Zion Park, we parked our truck and trailer, unhitched the load, and unloaded the ATVs. A guide took us into the dunes to show us where we could go, what we could do, and to repeatedly tell us not to roll the ATVs over. I did my best to ignore that last bit. I did manage to make some people nervous as they watched, though. I will sum the ATVs on the sand experience up thusly: if you can get a chance to do this, go do it. Holy crap is it fun, and way better than the go-carts in the sand we used as kids.

To get back to civilization, we got back into a truck, this time swapping for a 6.2L monster, and drove through Zion Canyon. The drive is scenic, leisurely, and a whole lot of picturesque.

Product Page: GMC Tow Like a Pro

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3 comments
RED CLIFF POSSE
What was your trip mileage and MPG. I travel a lot with a trailer loaded with toys: paddleboards , dirtbikes, and other equipment. I'm waiting to see a truck with trailer in tow get over 20 MPG, then I'll buy it! Two words....Toyota Diesel... I'm waiting!
Cwolf
Loading the trailer properly is critically important, but not as easy as it sounds. Trailer whip can be catastrophic (and the intuitive response to brake can make it worse).
Every "expert" said center my tractor on the trailer, but where is the tractor's center with an FEL and a ballast box?
The result was a near disaster.... the good news is the F-150's trailer system corrected the whip automatically.
We need better systems to assess the entire towing system weight distribution quickly & easily.
Bob B
@Cwolf - Look up the Weigh Safe hitch https://www.weigh-safe.com/ It has a scale built in to the hitch so that you can easily tell how much tongue weight you have on your trailer. You still need to know the approximate weight of the trailer to know how much tongue weight you should have, but at least having the scale built into the hitch takes the guess work out of the tongue weight.