| Limitations of SUV Towing
All the negative publicity surrounding SUVs and their generally poor reputation as towing vehicles may be because of their tendency towards "tailwagging" — also known as swaying. Although SUVs have their towing limitations because of their high centers of gravity and sometimes short wheelbases, we believe this behavior can be controlled as long as certain parameters are observed.
There are three things you need to tow safely with an SUV: 1) an SUV with enough mass and wheelbase to control the trailer, 2) a well-designed trailer, and 3) a hitching system that permits the tow vehicle to correct and control trailer sway.
The fly in the ointment — the one that causes the most trailering rollovers — is the bow wave from a passing truck or crosswind that comes out of nowhere when you least expect it. When it hits, the trailer starts to sway. If the tow vehicle lacks adequate mass and wheelbase, if the trailer has too much sail area (total area of the sidewalls in square feet), if an unforgiving hitching system is used, or if any combination of these comes into play, the trailer will swing out of control until it overpowers the towing vehicle. This is a recipe for disaster. (The illustration below shows how a well-matched tow vehicle and trailer will behave when hit by a bow wave.)
(Read illustration from bottom to top.)
 How
"tailwagging" begins.
You can't avoid Mother Nature, but you can work with her by learning the nature of your equipment and following safe towing procedures. One word you'll hear us repeat over and over in relation to towing is wheelbase — the distance from the center of a vehicle's front axle to the center of the rear axle. Wheelbase is the foundation for vehicle matching because wheelbase tends to be proportional to mass, and these are the two most important qualities a towing vehicle must have to control a trailer's movements. It's also a reason why SUVs can't tow a very large trailer, regardless of hitching equipment or trailer design. The other reason pertains to the sail area of the trailer. The greater the sail area, the more tendency it will have to sway when hit by a bow wave. Because there's an upper limit to the wheelbase and mass of SUVs, there's an upper limit to the size trailer they can tow under any circumstances. However, for low-profile trailers, you have a 10% latitude in wheelbase parameters because of the reduced sail area. Vehicle matching is the first rule of trailering. Besides pairing the towing vehicle's wheelbase and mass with the appropriate length and sail area of trailer, other aspects of trailer design must also be considered. Such aspects as location of water tanks, location and number of slideouts, location of generators and other heavy accessories, and trailer frontal area (total square footage exposed to oncoming air resistance) should be looked at. Some of this information can be gleaned from manufacturer's specifications. The three trailer design factors most critical for safe towing, other than sail area, are:
2) a back-of-ball ratio of at least 70% (with some latitude, depending on other factors), and 3) at least 15% of the trailer's GVWR available for payload. Although there's a wide variety of hitch types and classes available, you'll need some type of weight-distributing hitch for towing a travel trailer, and it will most likely be a class 3 or 4 hitch. If you opt for a fixed-ball hitch with sway control, you'll be limited by the the potential hazards. You'll want to avoid high speeds, rough roads, and pulling a trailer over 20 feet long. On the other hand, an articulating hitch is a sway controller in itself. Its movable joints allow the trailer to follow behind the tow vehicle almost like a fifth wheel. In fact, our parameters allow for a 10% reduction in wheelbase of the towing vehicle with the use of an articulating hitch, provided all other towing parameters are strictly observed. You can tow safely with an SUV by making the effort to arm yourself with knowledge and applying that knowledge in preparation for the road. If you're willing to do that, many enjoyable and trouble-free trailering experiences will be yours. (See Matching Tow Vehicles to Trailers)
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