How To Tow a Trailer

If you ever plan to involve yourself in activities such as boating, camping or some sort of automotive pastime, such as auto crossing or drag racing, then chances are you’ll need to do some towing. While it may seem scary, towing an average-sized trailer is really easier than it looks.

Two of the most important things to have when you tow are basic common sense and the ability to adjust your driving. In other words, when towing, everything you do while driving needs to be done at about half the speed when compared to driving without a trailer. When you turn, go much slower. When you accelerate, do it much easier. When you brake, allow yourself a great deal more space to stop. And when you change lanes, allow room for your vehicle and the trailer.

The types of things you are likely going to tow are a boat, a camper of some sort, or a car trailer that’s usually home to a race or show car. The following information on towing basics applies to just about any type of towing application whether the trailer is carrying a boat, a car, or any other item that needs a lift from point A to point B. The universal nature of this information is due to the fact that how much you can tow and what you tow with are mainly based on weights and capacities.

For purposes of discussion, let’s suppose you bought a boat and want to tow it to a lake. Towing a boat with a pickup truck is a very common way to go. As such, the tow vehicle is a major consideration when pulling a trailer, making that vehicle as important as what you’re pulling.

As far as cars go, a full-size body-on-frame, rear-wheel-drive car like a Ford Crown Victoria (rated to tow 2,000 pounds) or Chevy Caprice is a basic minimum for towing anything approaching the weight of a 2,000-pound trailer. For smaller trailers, a smaller car can work, but for hauling anything more than 2,000 pounds you’re going to need a truly tow-friendly vehicle. Ideally, a truck or an SUV is always a smart choice for towing that boat or camper. Even a compact pickup like a Ford Ranger or Chevy Colorado is going to be better than just about any car. For heavier loads (say more than 4,000 pounds) a half-ton truck like a Ford F-150 or Chevy Silverado will meet the needs of just about any of the trailer-towing basics we’re discussing here. But even among half-ton trucks, towing ability can vary. For example, an F-150 with a 5.4-liter V8 will have a much easier time towing a 5,000-pound load than one with a 4.6-liter V8 because it simply has more horsepower and torque. Furthermore, the engine isn’t the only thing that can handle a heavier load. The transmission, brakes and rear axle are also upgraded, along with the larger engine. Beyond a typical half-ton truck, a three-quarter (such as an F-250) or one-ton (F-350) can handle loads well beyond 5,000 pounds. For example, an F-250 with a 5.4-liter V8 and 3.73 gears is rated to tow 12,500 pounds. Properly equipped, an F-150 is rated to tow 8,000 pounds with a 5.4-liter V8, an automatic transmission and 3.55 gears. Besides the tow vehicle and the trailer, the other critical element is, of course, the hitch. Trailer hitches are rated according to the capacity of the load weight and tongue weight. Load weight is referenced in terms of Gross Trailer Weight (GTW, see chart at the end of article). Tongue weight is the downward force exerted on the hitch ball. This is usually calculated at 10-15 percent of the maximum rated GTW. The tongue is usually formed from the V-shaped merging of the trailer frame rails at the front of the trailer. The coupler of the trailer is what accepts the hitch ball.

Once you know how much weight you’ll be towing and that the weight doesn’t exceed the maximum towing capacity of your tow vehicle, you’re ready to determine the proper hitch. Many pickups and SUVs come factory-equipped with a Class III hitch, which is the most popular class of hitch. Most hitches bolt to the vehicle, and while some are welded, a bolt-on installation is the method preferred for attachment. For hauling any load (car, boat, camper, or whatever) a Class III hitch can handle up to 5,000 pounds. For heavier boats or campers, a Class IV hitch (up to 7,500 pounds) would be required, and you might want to consider a three-quarter-ton truck at this point as well. We’d recommend (especially on a compact or half-ton pickup if not already equipped) going straight to a Class III hitch, which is enough to tow most campers, car trailers and small- to medium-sized boats.

All Class III and above hitches are made up of two basic parts. The receiver part of the hitch is what actually attaches to the tow vehicle. It has a framework that’s bolted (or welded) to the vehicle chassis. The receiver is a large square tube that accepts a drawbar. The drawbar is a smaller square tube that slides into the receiver and contains the trailer ball. The drawbar is fastened to the receiver with a pin that slides through both pieces and is held in place with a clip. Drawbars come in a variety of heights to allow the trailer to ride at a level plane. For example, with 4×4 pickups, a drawbar can be selected that “drops” the ball to a lower level. The size of the trailer ball also varies. There are 1 7/8-, 2-, 2 ¼-, and 2 5/16-inch sizes, with the 2-inch size being the standard.

With your tow rig, hitch and drawbar ready go, you now need a trailer. Whether it’s a boat trailer, a car trailer or a camper of some type, the attachment to the tow vehicle is the same. In general, a dual-axle trailer is also more desirable. Dual axles provide better load distribution and in the event of a tire failure, there’s still one good tire on each side of the trailer, which makes the whole package easier to handle if that happens.

As you move to heavier trailers, you’ll want to start considering trailer brakes. The most popular type of trailer brakes are surge and electric. Surge brakes work hydraulically using the force of a forward shift in the trailer caused by deceleration to compress a fluid cylinder and apply its brakes. Electric brakes have a controller in the tow vehicle that senses brake pedal pressure using a hydraulic pressure switch plumbed into the tow vehicle’s system. Of course the heavier the load, the more you’ll want to consider trailer brakes. We’d recommend looking at trailer brakes for any GTW of more than 2,000 pounds.

As we mentioned at the beginning, your driving style when towing a trailer needs to change dramatically. If you’ve never towed a trailer before and you’re nervous about it, we’d strongly recommend seeking out someone who has had experience with towing. In general, you need to remember that when you are towing, you have considerably less room for margin of error. Your vehicle and trailer are much less maneuverable and nimble than your car or truck is without a trailer, and it’s critical that you always compensate for the added length the trailer adds when you change lanes so that you don’t run anyone off the road.

As far as added costs, besides the item you’re towing, there is the fact that your vehicle will use more gas. This is not insurmountable, however. In fact, our experience with towing a boat across the country revealed a smaller increase in fuel consumption than we originally anticipated. Driving from Los Angeles to Chicago in a Ford F-150 standard-cab pickup with a 5.4-liter V8, we averaged 16.5 mpg traveling at 75-80 mph over 2,363 miles. With a new boat purchase in tow, the F-150 managed 13.2 mpg at 55-60 mph from Chicago back to L.A. over 2,051 miles. The overall average for the 4,414-mile jaunt was 14.8 mpg. However, we’ll note that boats are usually lighter than travel or camper trailers, and because they are typically lower and more streamlined, don’t create nearly as much aerodynamic drag. A good-size travel trailer (5,000 pounds or more) is going to impact fuel economy considerably more than our results.

With heavier loads, the difference in fuel mileage between a gas- and diesel-powered truck can be enough to offset the added purchase price of a diesel. However, you’ll also want to factor in that these days, diesel fuel can be notably more expensive than gasoline; up to 40 cents a gallon in some instances.

Finally, you’ll want to consider the laws regarding towing. Every state has different rules and regulations for towing a trailer. We recommend checking your state’s laws regarding what’s cool with towing and what’s not. We can tell you that, at a minimum, all trailers need to have working taillights and brake lights and that most states require registration of the trailer with the Department of Motor Vehicles.

With the right tow vehicle, a proper Class III or bigger hitch and a trailer that’s in good repair, you’ll be on your way to the lake, the campgrounds or the racetrack with your hobby horse of choice in short order.

Besides the basics we’ve covered, there are several other more specific areas that you might be curious about. Let’s take a look.

1. How much extra room do I need when turning with a trailer? It’s difficult to give an exact distance since it depends on the length of the trailer. With a typical boat trailer, making left turns isn’t a big deal. But for right turns, you’ll want to compensate at least some, initially, until you can determine how much space you need. With longer trailers, you’ll need to “go wide” to some extent like big rigs do so you don’t hit a curb with the trailer while in the middle of a right turn. Think, for example, of how a big rig often makes right turns at least one lane over to the left in smaller intersections so the trailer doesn’t hit the curb (or a sign or stoplight) as it travels through the turn. You need to apply the same logic when towing a trailer, even though your trailer isn’t nearly as long.
2. How much does the typical 3500-pound trailer affect braking distances? Obviously, the added weight of any trailer is going to affect braking distances significantly in an emergency situation. It’s difficult to pinpoint exact distances since much of it depends on factors like if the trailer is equipped with brakes and how much tongue weight there is. Testing is not commonly performed to determine braking distances with trailers in tow. But, the best way to be safe is to avoid emergencies in the first place. Allow as much space as possible between you and those in front of you. A good place to start is to double the standard “two-second rule” when following behind another vehicle. Allow double the amount of space between you and the vehicle in front of you when towing a trailer. And the heavier the load, the more space you should allow.
3. Why are body-on-frame vehicle designs better for towing than unibody vehicles? Part of the reason is that you can attach the receiver part of the hitch directly to the frame of the vehicle. On a vehicle with unibody construction, there’s not as solid a place to bolt the hitch to the vehicle. With a body-on-frame design you’re pulling the trailer with the actual frame of the truck or SUV rather than just having the trailer attached to the body of the vehicle.
4. What can happen if I exceed the tow rating for my vehicle? The tow rating of any vehicle is based on numerous factors. The best advice is do not exceed the tow rating for any vehicle. If you do, you’ll be overloading the suspension, overextending safe braking distances, and experience further reduced and possibly unsafe passing ability. You’ll also overextend brake component capacities and, in some situations, encounter premature brake fade. Furthermore, you won’t be doing any favors to the engine and drivetrain, and the chance of eventual transmission failure is also possible.
5. What should I do if the trailer starts to sway at a high speed – i.e. if “the tail starts wagging the dog,” so to speak? If you get to a point where you experience trailer sway, it’s likely that something else is wrong. The problem could be insufficient tongue weight. If you have a travel trailer, shift heavier items to the front and lighter ones to the rear. With a boat or car trailer, move the vehicle forward. There are also a number of sway-control devices available to stop this condition before it begins. If this condition exists, the trailer and tow vehicle haven’t been set up properly. Whatever the case, the first thing is to avoid panic. It’s also likely this condition will occur gradually. Don’t ignore any first signs of trailer sway. But if it starts, slow down by taking your foot off the accelerator. Let vehicle speed decrease but do not put your foot on the brake pedal, which can make the situation worse. Once you’re down to a safe speed, carefully apply the brakes and stop. You should then readjust the load or determine what else might be causing this condition.
6. How do I back up with a trailer attached? If you’ve never backed up with a trailer, the first thing we’d recommend is to go to an empty parking lot or somewhere else with lots of space and practice to see what happens when you back up with the trailer attached. Also, don’t rely on rearview mirrors. Turn behind and look at the trailer. Basically, when you turn the wheels of the tow vehicle to left, the trailer will go to the right; turn the wheels to the right and the trailer will go left. To control the direction of the trailer while backing up, you need to keep this “reverse action” concept in mind. Oftentimes, you’ll also have to pull forward and start over again to position the trailer exactly where you want it. Small and shorter trailers are often more difficult as they react much more quickly to steering wheel input. If possible, it’s also very helpful to have a spotter watching at the back of the trailer. If nothing else, they can yell “stop” before you back into something and cause damage to the trailer or any other item. Also, don’t forget to look at the front of the tow vehicle, too, because when you turn while backing up, the front of the vehicle could possibly swing out far enough to hit something.
7. When I attach a trailer to my tow vehicle, the tow vehicle sags significantly. What can I do to keep that from happening? Most trucks are setup to tow and haul, so their suspension probably won’t sag when a trailer is attached. Passenger cars and some SUVs have softer suspensions and may need some help. A weight-distributing hitch should be used in these instances. It helps to evenly distribute the weight between the front and rear axles of the tow vehicle. The spring bars of a weight distributing hitch work similarly to the handles of a wheelbarrow, lifting on the back of the tow vehicle and shifting the weight forward. Airbags or air shocks can also help the rear suspension when towing. When in doubt, seek the help of a qualified RV shop.
8. Some minivans such as the Chevy Venture are rated to tow 3,500 pounds. Are front-wheel-drive vehicles OK for towing? How about all-wheel-drive? What are the benefits and detriments of each type of system? As long as you don’t exceed the tow rating of the vehicle, any front-wheel-drive car, SUV or minivan will tow fine. The main consideration with using a front-wheel-drive vehicle as a tow rig is the fact there will be less weight over the drive wheels, which could be a factor in such situations as towing up a steep and wet boat ramp. An all-wheel- or four-wheel-drive vehicle for towing also works fine, but keep in mind that an all- or four-wheel-drive version of any vehicle will usually have a lower tow rating than the same vehicle in a two-wheel-drive version. Obviously, you don’t need an all-wheel-drive vehicle or a 4×4 truck for towing a trailer on the highway. If you’re thinking about a vehicle purchase and towing is a large reason for buying that vehicle, then a rear-wheel-drive truck or SUV is the best way to go. All- or four-wheel-drive vehicles will tow just as well, but the vehicle will use more gas due to the added weight of the components.
9. If a tire on my trailer suffers a blowout, are there any differences to changing a trailer tire from a vehicle tire? Not really. Any safety precautions you use to change a tire on a car apply to the trailer, too. Chock the opposite side wheel, use a heavy enough jack to support the trailer’s weight and loosen the lug nuts some first before raising the wheel off the ground. That way, the wheel won’t spin while it’s in the air and you’re trying to loosen the lug nuts.
10. Do I need those extra-wide mirrors for towing? That depends on the width of the trailer. For the average boat or car trailer, you’ll likely be able to see down the side of the vehicle and trailer with the factory-equipped side-view mirrors. But for wider trailers, you’ll need side-view mirrors that stick out far enough so you see down the side of the trailer. For example, a narrower SUV like an Explorer towing a wider camping trailer might need to be equipped with aftermarket towing mirrors that match the width of the trailer so the driver can see down both sides. In addition, it’s illegal to tow without mirrors that don’t allow the driver to see down the entire length of the vehicle and trailer. Check your state’s laws for specific guidelines regarding towing mirrors.
11. Current full-size Chevy/GMC trucks have a tow/haul mode for the transmission. How does it work and why don’t other half- and three-quarter-ton pickups have this feature? The tow/haul mode found in the current-generation Chevy Silverado and GMC Sierra pickups delays upshifts for more effective towing and hauling. The higher upshift speeds and firmer gear changes are due to an increase in line pressure. While other pickups don’t have this specific feature controlled by a button on the end of the shifter, we took a look in a 2000 Ford F-150 owner’s manual and discovered a similar type of function. Although there isn’t a specific control for it, Ford’s “adaptive learning strategy” means the transmission “knows” you’re carrying a load or towing a trailer and adjusts the transmission’s shifting schedule accordingly.
12. What’s the best way to ascend a mountain when towing? What about descending? In general, you want to keep things steady and consistent. That means when you’re going uphill you don’t want the transmission hunting between gears, such as third and fourth. Depending on the weight of the load and the grade of the hill, you’ll likely want to hold the transmission in third gear (locking out overdrive), which will also keep the engine in the range where it makes the most torque. Keeping the transmission out of top gear will also prevent you from lugging the engine or necessitating undesired downshifts when you accelerate out of turns at slow speeds. It’s the same for a manual transmission. Driving in the next lower gear will keep the engine in its best operating range. Going downhill, you want to use a combination of the engine and the brakes to keep your speeds safe. Don’t ride the brakes too much and get them too hot. Downshift to a lower gear and use the engine as a brake on steeper hills and then, when needed, use the brakes sparingly to slow down from there. When the hill levels off a bit, you can upshift to the next gear and keep your frequency of brake use about the same. It’s all a give-and-take in relation to the grade of the hill, the weight of your load and the gear ratios in the transmission, which all need to be considered when it comes to keeping your speeds safe going up and down hills.