The truck you see here has 350 horsepower, but it's not a racehorse. And though it is a 4x4, with straight axles and low-range gearing, it's not a mountain goat, either. A Super Duty is more like a Clydesdale - stout, gentle, and enormously willing to pull. This pickup was made to haul something that probably already burned down a lesser truck. Chances are, you wouldn't buy a Super Duty unless you had a problem load. This is the kind of truck that takes your big problem and makes it go away.
You can get Ford Super Duty pickups with Gross Vehicle Weight Ratings all the way up to 16,500 pounds on the F-450 or, for that matter, 19,500 on the F-550. With one of those and a fifth-wheel hitch, you can tow up to a 24,000-pound trailer, making a rig that could weigh up to 33,000 pounds and still be within the recommended capacity.
As Super Duty pickups go, our test unit is one of the lightest-duty configurations, a 10,000 GVWR model, with single rear wheels, 6.5-foot box, four-wheel drive, and 3.73 axle gears. It's rated to tow up to 12,500 pounds with a weight-distributing hitch. With a conventional weight-carrying hitch, the max towing recommendation is 6000 pounds and, according to the tire label, the front axle can handle 5600 pounds and the rear 6100 pounds of load. The third critical factor is that the Gross Combined Weight can't exceed 23,500.
That sounds like a lot of weight, but actually staying within these requirements can be problematic for any trailer owner.
Our load in this case was a 21-foot Skipjack, a rugged older boat loaded with fuel and camping gear. It's not a huge boat by any means, but it is a whole lot heavier than a modern ski or bass boat. Mounted on an older trailer equipped with surge brakes, this kind of load presents a challenge because the tow vehicle isn't given the advantage of a weight-distributing hitch or electric brakes. Like most people, we had no idea what our boat really weighed, so we made a trip to a certified truck scales and got in line with a bunch of big-rigs.
Turns out our combination weighed 13,700 pounds with load, hitch, and driver. Subtracting the curb weight of the vehicle, measured at 7405 pounds, means our boat and trailer weighed 5295 pounds, comfortably under the 6000-pound margin. Likewise, our GCWR was well under the 23,500-pound spec. So we could've loaded up another 600 pounds of gear and people and dogs, and if we were heading for the river, we probably would have.
However, we also took the trouble to weigh the truck alone "with all four tires on the scale" but with the boat still hooked up. The idea was to approximate the tongue load, which should be 10 to 15 percent of the total weight of the trailer, or in this case, no more than 779 pounds. With the boat still resting off the scales, the truck and driver weighed 8820. That suggested the tongue load could be as high as 1115 pounds, which would be excessive by about 335 pounds, if our method is correct and the scales are right on.
The better way to judge tongue weight is to unhitch the trailer, position it with just the hitch end parked on the scales, and weigh just the hitch end. It's not a practical process when you're holding up a line of big-rigs 10 trucks long, but it would be more accurate. Should there be more weight on the front of the hitch than you expect to see, you'd be well advised to rearrange the gear in your trailer to put more weight toward the rear of the trailer. Visually, our truck and trailer looked about level, but we still took some time to shift what had to be at least 150 pounds of tools, spare batteries, and emergency equipment to the rear. In the end, it's likely our setup was slightly heavy on the rear axle. That axle, rated to carry 6100 pounds, was probably not in jeopardy, but we'd be driving with a chassis that had less-than-ideal front-to-rear weight distribution. That could affect steering and braking, giving the front axle less braking and steering power than normal, and putting the braking burden more on the rear axle alone.