Towing Tutorial
by Ann Job, www.advancedairhitch.com

Frequently Asked Questions

Towing a load behind your vehicle involves a lot more than hitchin' up and movin' on down the road . . .
Know what you can tow.

It sounds simple enough, but towing a camper, boat, trailer or another vehicle safely involves a lot of know-how.
Here are some basic tips:

Learn the Lingo - Towing has a language all its own.

GVWR Gross Vehicle Weight Rating - Despite what it sounds like GVWR is something different than just the weight of a vehicle, for example. GVWR is the combined weight of a vehicle with all its passengers and cargo added in, and it's a key number to know before you start to tow.

GCWR Gross Combination Weight Rating. This is the maximum allowable weight of the loaded-up trailer and the tow vehicle - with all its passengers and cargo, too-added together. It's a key measure for you to check to ensure you are not putting too much of a burden on your tow vehicle and risking costly damage.

TW Tongue Weight. It relates to the amount of trailer weight that presses down on the trailer hitch at the back of a tow vehicle. Having too much or too little tongue weight can affect the safe handling and driving of your tow vehicle.

Use the Proper Vehicle

You need to know the tow capacity of your vehicle and make sure it's sufficient to tow the trailer, boat or camper.

First, determine the approximate weight of the trailer or boat. Include the weight of any equipment, cargo and fluids the trailer or boat will have in or on it. Some tow experts advise that you add 10 percent or 15 percent on top of this, just to be on the safe side. This is the Gross Trailer Weight (GTW).

Then, check to see if the tow vehicle - the truck, sport-utility vehicle, van or car you plan to use - has enough towing capacity. Vehicle manufacturers provide a tow rating in their owner's manuals. Cars tend to have lower tow rating than trucks, and light-duty trucks have lower tow rating than do heavy-duty models.

If you are purchasing a new vehicle that will be used for towing, review the available options to see if you want to add a transmission-oil cooler, a heavy-duty battery, heavy-duty shock absorbers and other tow equipment. These kinds of items can help your tow vehicle manage the stress of a heavy load, and oftentimes some or all of the items may be available as a towing package.

In addition, consider adding trailer mirrors for the front doors of your tow vehicle. These larger mirrors can improve a driver's view out to the side and back of the trailer when compared with standard vehicle mirrors.

No matter if your tow vehicle is new or old, keep the owner's manual and vehicle manufacturer towing guide handy. They contain many of the important numbers - tow rating, GCWR, etc.- that you will need to know.

Have the Right Hitch

There are many hitches for towing, covering several rating classes. You need to find one that will fit your needs.

Obviously, your hitch has to be able to handle the GTW you plan to tow. For example, a Class I hitch can handle up to 2,000 pounds GTW and up to 200 pounds of tongue weight.

Hitches also differ in how they mount on a tow vehicle.

Weight-carrying hitches bolt on the tow vehicle's frame and/or bumper, and are commonly used for small- to medium-size trailers.

Weight-distributing hitches, used with hitch receivers, distribute the load among the wheels of the tow vehicle and the wheels of the trailer to provide improved steering and braking. Ford's RV and Trailer Towing Guide notes that these hitches "are only 'required' for Class IV applications" and generally aren't used for loads under 5,000 pounds.

The fifth-wheel hitch is uniquely mounted inside the bed of a pickup truck and puts more of the trailer weight directly over the tow vehicle, rather than behind it.

Hitches may need to be supplemented for improved sway management of your trailer. Hadeer A. Konja, supervisor of Dodge Truck vehicle development and synthesis, encourages anyone towing more than 3,000 pounds to consider adding a stabilizer bar that hooks to the hitch and the receiver. The stabilizer can reduce trailer sway, he said.

Pack Carefully

It is important to think about weight distribution as you pack your trailer or camper. The goal should be to properly position weight to keep your vehicle and trailer as stable as possible. Therefore, refrain from piling heavy items on the sides of a trailer or camper. Also don't load everything into the back of a trailer. According to Ford's RV and Trailer Towing Guide, you want 60 percent of the cargo weight in the front half of the trailer and 40 percent at the rear, within limits of the tongue weight.

"The key is to not exceed the tongue weight," Dodge's Konja said, adding that tongue weight is determined by the manufacturer of the hitch.

Secure items in and on the trailer tightly. You don't want them to break loose or jostle around and affect weight balance and handling.

Is Towing Safe?

The answer to this question is "Yes"...and "No". Let me explain.

Towing a trailer can be dangerous to your emotional and physical health, as anyone who has towed a poorly built, unstable trailer will readily testify.

A uncontrollable trailer can push you down unintended paths, break away and select its own direction, snake erratically all over the road, and perform spectacular feats -- land crosswise, on its side, upside down, whatever. It will most likely end up being totally destroyed, taking you with it!

However, a trailer, which is properly designed and correctly loaded, can be a delight to own and tow. However, how do you know whether your trailer is in this category? Pre-trip safety checks and a regular maintenance schedule will go a long way toward making your trailer friendly...assuming, of course, that its basic design is inherently sound. Inspect your trailer thoroughly before each trip to make sure that its mechanical systems operate correctly. These pre-trip inspections will reveal which parts need attention before something happens.

OK...where do we start? How about at the beginning -- at the hitch. Be sure the hitch on the tow vehicle is adequate (plus 10% - 20% -- more is better in this case) to handle the net weight of the trailer. A 5000-pound hitch just is not going to cut it if the trailer weighs 7000 to 8000 pounds. Having your trailer going' east on I-10 while you're headed north on I-17 because your hitch broke can be kind of embarrassing

Check the hitch carefully, especially if it is the "bolt-on" variety, and make sure all connections are tight. Be certain that the big nut that holds the ball to the hitch is tight, too, for it will have a tendency to loosen, even with a lock-washer in place. Trust me; it does happen.

When you have checked that, you are ready to hook up to the trailer. Once the coupling on the trailer is centered over the ball, lower it, making sure that it drops completely down on the ball. Smearing a little grease on the ball will make this easier and will protect the surfaces that slide in relation to each other as you drive down the road. When all is secure, close the latch (locking mechanism) and lock it with a small padlock. That will prevent it from opening accidentally as well as deter vandals or thieves.

Now connect the safety chains or cables. These are very important and most states require two (2) of them to be used. Hook them to the frame of the tow vehicle, not to the hitch, and be sure to cross them under the trailer's tongue (In the event of a break-away, the chains will catch the tongue and suspend it above the roadway). Make sure that your chains are long enough to allow turns, but short enough that they don't drag the ground or allow the trailer tongue to be pushed forward into the fuel tank of the towing vehicle in case something does break (Sparks and gasoline, when combined, provide a spectacular pyrotechnic display which may be quite frightening when observed in one's rear-view mirror.).

OK. Plug in your electrical connectors and test all your lights. Now check the trailer brakes and make sure the breakaway system is operating correctly.

There are so many different types and makes of hitches available that it would be impossible to discuss all of them, so let it suffice to say that with 10% to 15% of the trailer's weight on the tongue, your tow vehicle should be level and so should the trailer. Both units should also be level with each other. Neither the nose nor the tail should be high or low.

Ahhh...trailer sway. What about it? "Sway" is one of the most serious, dangerous, and frightening conditions, you may encounter when towing a trailer. Most well designed trailers will track straight and true under almost any circumstances. However, sway lurks as an ever-present danger even so. Many folks assume that the trailer is the sole cause of sway, but that is simply not true.

There are several causes of sway. For the tow vehicle...
1) Wheelbase is too short
2) Rear overhang is too long
3) Rear suspension is too soft
4) Rear-end weight is too much
5) Rear cornering stiffness is too low

For the trailer...
1) Tongue weight is too little OR too much
2) Center of gravity is too high
3) Tongue length is too short
4) Trailer frame is too flexible
5) Trailer suspension is too soft

Bear in mind also, that the wrong tires and/or improper inflation thereof may be critical factors. Be sure the load rating of your tires is correct for your application and that all the tires are properly inflated. In addition, one other thing...NEVER mix bias-ply and radial tires on the same vehicle. Their characteristics are much too different and will adversely affect the handling of the trailer or tow vehicle.

If you discover any defects in ANY of the above, correct them BEFORE you venture out on the highways with your trailer.

"If I experience trailer sway while driving, what can I DO about it?" you ask. Good question. There are basically two types of sway...MARGINALLY STABLE and UNSTABLE.

Marginally stable sway is a fairly constant weaving from side to side by the trailer -- it's always there but doesn't get out of hand. This is often more of an annoyance than a threat. As you increase your speed, however, the weaving from side to side increases as well, eventually leading to the second kind of sway -- Unstable! This is where each side-to-side oscillation is wider than the one preceding it -- until the trailer either jackknifes or leaves the road, taking the tow vehicle, and you, with it. If you constantly drive at the upper end of the marginally stable region, you are begging for trouble. I would say that you have a death wish.

However, if unstable sway begins, DO NOT hit the brakes or try to steer out of it. Hold the steering wheel steady and firmly and back off the throttle.

If you are lucky, your rig may slow into the stable area before anything really nasty happens. Your best bet, however, is to think about all the factors that may cause sway and try to avoid them in your rig.

Trailer Towing Q&A, (Reprint of an article by Miles Cook, Edmunds.com

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 set up 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 4x4 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'sin 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.

Additional Trailer Towing Information:
Towing Your Horse Trailer - Towing Tutorial
How To Tow A Trailer
Your first trip with your Trailer
Tow Vehicle Considerations
Horse Trailer, Vehicle Safety Check
Trailer Towing Q&A