5th-Wheel Hatchbacks Trailers: Some Ideas Should Stay Dead

Michael GrossmanAugust 30, 2016 7 minutes

One of the more interesting parts of American history is that so much of what we take for granted started with someone saying, "Wouldn't it be neat if...?" Then that person either invents something that can do the task they were thinking of, or sparks an idea in another who solves that problem.

Of course, we only hear about the success stories, which stick with us far longer than the numerous failures, which pop on to the scene and quickly vanish. In the pantheon of failed ideas is one from the mid-70s, a decade of such bizarre excess from pet rocks to disco that it might rightly lay claim to the weirdest decade ever.

The 1970s existed at a weird intersection where mass production and mass marketing had reached maturity, but other game changing technologies like personal computing, telecommunications, and biotechnology were in their infancy. With existing markets pretty-much fully exploited, manufacturers had to get weird in order to find the next great product. Into this setting came the 1974 VW roof-mounted trailer hitch. That's right, having solved just about every other problem known to 1970s man, some folks sought to solve the problem of needing a large car or truck in order to tow stuff.

The result of this endeavor was a one-of-a-kind, pretty ingenious towing set-up for a Volkswagen Beetle. Just watching that video, you see a truly unique and intriguing product. It truly is a neat little marvel.

We could sit back and have a comfortable chuckle, while playing Monday morning quarterback to history, if not for the recent suggestion by an author at The Truth About Cars to revive this truly horrible idea.

The Case Against the Fifth-Wheel Hatchback Trailer

While the fifth-wheel hatchback trailer is a quirky, amusing anomaly from the past, incorporating the idea into modern vehicles is a truly horrific idea. The author asserts:

"In 2016, if you towed a camping trailer with anything other than a heavy-duty pickup, Mike Rowe and Denis Leary would take you out back and shoot you repeatedly with Blue Oval masculine marketing tripe."

Sure, the machismo in those ads may be a little over the top for some tastes, but the underlying point is that there are vehicles that are specifically designed for towing. However, there is nothing super masculine about the fact that such vehicles exist. In fact, to deny that some vehicles are built for towing and some vehicles aren't is to break with reality.

Such a break is exactly what the author of the article experienced. It's undeniable that the vast array of car choices in today's market are the result of carmaker's desire to increase sales by filling every possible niche. Since there is no such thing as a full-sized compact, super-fuel efficient, towing machines with room for between 2 and 16, car design is by necessity a series of trade-offs. The point is that we don't use the largest, least-fuel efficient vehicles for towing because towing and gas guzzling go hand and hand, but because they're the best tool for the job. The Swiss-army knife vehicle would be as bland and ill-suited to its task as the Swiss-army knife is as a tool. It gets the job done, but not well.

Hatchbacks Aren't Designed to Tow Things

As cool as it would be to hook up a trailer to a Smart Car, it would be an absolutely terrible, borderline reckless idea. The first problem is that fifth-wheel hatchback trailers attach directly to the roof of the car. Even the super heavy duty trucks that the author mocks are not designed to tow things with the roof as the point of contact between the vehicle and the trailer.

If you take a step back for a moment and think about how vehicles are designed, engineers account for the various stresses that a vehicle is likely to encounter. From the torque of the engine, to the force of the car pushing against the road, all the way down to the way the vehicle reacts when hit from the front, back, and sides, these factors all play into the design and construction of a vehicle. One thing engineers don't consider is applying several thousand lbs. of pressure to roof of a vehicle. This is true from nifty little hatchbacks, all the way up to super heavy duty full-size trucks.

The problem with this significant force from an unexpected direction is that it is not accounted for in the design. This can result in numerous problems. The biggest is that it can have wildly unpredictable effects on how crumple zones function. Crumple zones are essential to the improved safety of modern cars. They are designed to absorb and disperse the forces of an impact in areas of the car outside of the passenger compartment. As a result less force makes its way to the occupants of the vehicle, increasing their chances of survival.

Introducing unexpected forces can greatly decrease the functionality of this life-saving design features. Given that smaller cars are already at a disadvantage in an accident, due to the lower amount of material available to absorb the force of an impact, it seems that anything that exacerbates the problem, like the fifth-wheel hatchback trailer, would be a non-starter.

Hatchbacks Don't Have the Breaks Necessary for Towing

In a small car an extra few hundred pounds makes a huge difference in performance. Just having 3 passengers in a small car, with their additional 500 lbs. creates a noticeable difference in braking performance . It takes a bit longer to stop and a prudent driver has to keep a little extra distance between their car and the vehicle in front, just to account for this fact.

A fifth-wheel hatchback trailer would be at least an additional 1,500 lbs, that's on top of the close to 3,000 lbs that most compact cars weigh. To tow that much weight, plus any passengers that a driver may have, would require the driver to keep such a large distance between their car and the one in front of them that it would be practically impossible in real world conditions. Even if they tried slowing down to keep that distance, other drivers would certainly fill in the wide-open space necessary to ensure that their brakes will get their vehicle and the trailer stopped in time.

Hatchbacks+Towing=No Acceleration

In addition to creating unnecessary and potentially dangerous issues with the brakes, the additional weight from towing would be a nightmare when accelerating. Take for example a road like the North Dallas Tollway, with its short on-ramps, constant construction, and lack of shoulders in many areas. With just one person in a compact car, it accelerates relatively smoothly to highway speeds and gets up to 60 or 65 mph in most instances. While the posted speed limit on much of the Tollway is 65 mph, the reality is that traffic is usually moving anywhere from 70 to 80 mph. So on a normal day, people merge into traffic that is going a touch faster than their car.

It's a problem if one were to add another 1,500 lbs. to the equation, no amount of pushing the engine harder is going to make up that difference. The only solution is to have more room to accelerate. Given the limited confines of many roads, there are many places in Dallas where that just isn't going to happen and one would be lucky to get the hatchback-trailer combo up 40 mph.

Merging under ideal circumstances is tricky and one of the more dangerous parts of driving. Merging with vehicles going twice as fast as yours isn't about skill and good decision making, but luck.

The Rickshaw and the Miata

A roof-mounted trailer hitch is the equivalent of attaching a rickshaw to a person's hair. If may be difficult to visualize the forces at play on a car, but the rickshaw makes it easier to see how things can go terribly wrong.

Suppose a person with the hair-mounted rickshaw harness is rickshawing down the road when they suddenly crash into a barrier a waist high. One of two things is likely to happen. Either the force will rip their hair out of their scalp, or if it holds, it will push the person the rest of the way over the barrier, while the rickshaw goes crashing into the barrier where the person was.

Either way, the results would be far worse than if the rickshaw were attached via a shoulder or waist harness, allowing the poles of the rickshaw to absorb the momentum of the cart in an accident.

A real world example would an interview from years ago with the designers of the Mazda Miata. For years, many fans of car clamored for a hatchback or a coupe version of the vehicle. The designer said that the design team had looked into the possibility, but adding the extra weight, plus whatever weight that drivers would invariable store in the back of the car would throw off the weigh balance of the vehicle and render it unstable.

For this reason, Miata's were only made as convertibles. So the engineers behind one of the best, from a performance perspective, small cars ever built, decided that added weight in the back of a small car was just too dangerous, but an author at a car blog thinks that it should happen to show those hyper-masculine large truck operators? You can make up your own mind, but I'm inclined to side with the engineers on this one.

No Disco. No Pet Rocks. No Roof-Mounted Fifth-Wheel Hatchback Trailers

Wouldn't be great if little hatchbacks could tow things easily? It would be even better if they could fly or were converted to amphibious uses. Heck, while we're at it, let's just dig up an old Saturn V rocket, strap compact cars to the top and send them to the heavens, like a freight train of awesome non-stop to the moon.

The point isn't to belittle the folks over at The Truth About Cars for longing for the return of a really bad idea. Instead, it is important to peer past the shiny "wow, that's neat" veneer and see the very real danger that lurks beneath the idea.

Getting a truck for towing isn't about machismo, anymore than getting a legitimate ax makes more sense than a hatchet if you're cutting down good-sized trees. Despite our nation love affair with cars, at the end of the day cars are like any other machine, a tool. Just like you could make a million modifications to make a hatchet more suitable for cutting down large trees, at the end of the day it will never be as practical or as safe as the cheapest ax.

If you want 1970's nostalgia, re-watch Dazed and Confused or That 70's Show, don't ask people to bring back dangerous ideas that faded into history for a reason.