Usually a “Beginners Guides” is written by experts for beginners. Well not in this case. Instead this is a “Guide to Towing” by a beginner. If you are new to towing or thinking about towing, this article should open your eyes as to what you are getting into. If you are an experienced tower, hopefully there are a few gems in here for you too.
There’s nothing like a 3,500 mile trip to focus one’s attention on the task at hand. How tight should a tie down be? What is a trailer brake controller? How do I backup? Are you ready? Let’s dive in.
Since this is a Porsche newsletter, the focus will be on towing your favorite sports car. But almost everything discussed here will be applicable to trailers with a total weight of 3,000 to 7,000 pounds. The likely tow vehicle may be a Cayenne or Macan, but if not, most larger SUV’s and pickups are good candidates. For simplicity, I’ll refer to the tow vehicle as the truck and the vehicle being towed as the car or sports car.
Before getting into the details, I should mention that there are lots of opportunities for things to go wrong when towing. While I am happy to report that our road trip to Texas was completed without incident, there were plenty of “duh” moments where things could have gone awry. I cannot overemphasize the need to do things slowly and methodically — double check your work often. Being in a rush, especially when you are new to towing, is not going to end well. As you gain experience, tasks become easier, but you always have to respect the size, weight, and value of the elements you are dealing with. I think you’ll get a sense for this as you read between the lines of this article!
This article is by no means a complete guide to towing, but rather an introduction. For much more detailed information, see the links at the end of the article.
Trailers and Tow Vehicles
Why get a trailer? There are two primary reasons: when the distances being traveled make driving the sports car unappealing or when you want to bring more gear with you than will fit in the car. A typical scenario is someone who is gaining more experience at track events and eventually wants to travel to more distant venues or bring more equipment to the track (usually things like tires, jacks, tools, etc.).
Open vs enclosed trailers? Open trailers are less expensive and are lighter. With some exceptions, enclosed trailers are the opposite. For short distance trips, an open trailer makes a lot of sense. As distances lengthen into multiday trips, enclosed trailers become more attractive as they offer greater security and protection from the elements (especially appreciated by the concours crowd). Given our Reno winters, an enclosed trailer provides more freedom to commit to events that require crossing the summit.
Trailer brakes? Any trailer used for towing a vehicle should have trailer brakes. These brakes are typically electrically activated. There are also surge brakes (hydraulically actuated), and electric over hydraulic brakes (hybrid of electric and hydraulic functions). I’ll focus on the electric variety. These are drum brakes, and the best ones are self adjusting and thus require less maintenance.
Tow vehicles? The weight of the trailer, sports car, and gear will be a major factor in determining the appropriate tow vehicle. For instance, a Cayenne can tow 7,700 pounds while a Macan is capable of towing 4,400 pounds. These figures may vary from model year to model year and between models (e.g. S vs. GTS vs. Turbo), so be sure to check the rating of your specific vehicle. The total weight of the trailer and contents is called the gross trailer weight or GVWR (gross vehicle weight rating).
Other than towing capacity, the next most important feature of a tow vehicle is comfort. How are you going to feel after a 3,500 mile trip? Our trip was made much more pleasant by the outstanding comfort of the Cayenne, especially the seats. Absolutely no “butt fatigue” after hours in the saddle.
If the thought of owning a tow vehicle puts you off, then consider renting. Enterprise Truck Rentals offers well equipped ¾ ton diesel trucks with ample towing capacity at very reasonable rates.
Towing packages? Hopefully your truck has the factory towing package installed. This will greatly simplify things. Towing packages can retrofitted by the dealer or your mechanic, but it is a much more costly proposition than getting it OEM. A towing package typically includes a hitch receiver, the trailer wiring harness, and necessary vehicle upgrades (i.e. lower gearing, additional engine cooling, etc.).
Receiver? The receiver is the square black tube sticking out under the back bumper. The receiver accepts the ball mount. Class I and II receivers are 1-1/4” x 1-1/4” and are suitable for a maximum gross trailer weights of 2,000 and 3,500 pounds, respectively. Not suitable for vehicle towing. The class III and IV receivers are 2” x 2” and have a maximum gross trailer weight ratings of 6,000 and 12,000 pounds, just what we need.
Ball mount? The ball mount links the truck to the trailer, also referred to as the drawbar or hitch. It is a platform that is inserted into the receiver and secured with a pin and clip. The balls come in different sizes. The two most common sizes are 2” and 2 5/16”. The larger the ball, the greater the towing capacity, so you’ll likely be using the second one. You’ll want to get an adjustable ball mount which allows you to vary the height of the ball (see below), which, in turn, determines the height of the trailer’s tongue and thus how level the trailer sits.
Ball height? This is the height of the ball top measured from the ground. Trailer manufacturers will often provide a ball height recommendation for the trailer. Some will state this as the unloaded ball height and they will assume a drop of 2-3” when the trailer is attached. I find it better to ask for the loaded height, which, understandably, will vary based on the amount of weight placed inside the trialer.
Tongue? The part of the trailer that extents from the cargo area. The coupler is mounted to the tongue.
Coupler? Mounted to the end of the tongue, the coupler connects to the ball mount.
Tongue weight? This is the weight that the trailer’s tongue exerts on the ball mount. For a Class III trailer commonly used for vehicle towing, the maximum tongue weights are typically 300-600 pounds or 10-15% of GVWR. Often the trailer manufacturer will provide the optimum tongue weight. You can control the tongue weight by positioning the car either more to the front or more to the back of the trailer.
Measuring tongue weight? Okay, but how do I measure the tongue weight? Well, you can set the trailer’s jack on a quality bathroom scale and measure it. Or you can purchase a ball mount like the Weigh Safe with includes a built in scale.
Electrical connectors? The standard trailer electrical connectors are either 4 or 7 pin (also referred to as 4 and 7 way). Four pin connectors do not provide a signal for the braking action of the trailer, so if this is what your tow vehicle has, it will need to be upgraded to a 7 pin.
Trailer Necessities & Accessories
Air suspension? If your truck has air suspension, you will quickly learn to love the convenience of being able to raise and lower your vehicle at will along with the comfort of driving level (as opposed to having the rear end sag). When towing, you’ll probably want to drive in the “normal” ride height position as this is where the alignment is set and thus will result in optimal tire wear. The advantage of adjusting the height comes in handy when hitching, unhitching, or when you need to raise the tongue of the trailer to back the car out.
Brake controllers? I was very surprised to find that if your tow vehicle has a 7 pin electrical connector required for controlling the trailer’s brakes, it is probably not doing so! Even on a Porsche! I could find no mention of this in the Cayenne manual. It seems as if the 7 pin connection is “brake controller ready,” but not “brake controller functioning.” So what is a brake controller? It is a device about the size of a radar detector that mounts under the dash (a very attractive addition to the Porsche interior) and sends an electrical signal via the 7 pin connector to the trailer activating the trailer’s brakes. The controller allows you to set the braking strength which will vary depending on whether the trailer is loaded or empty. If your tow vehicle has the factory tow package, then chances are that it is pre-wired for a brake controller. The Tekonsha Prodigy P3 is a popular brake controller and costs about $125. It includes a generic wiring harness and model specific ones are available for many truck makes (but not Porsche).
Bridles? Unfortunately, most tow hooks are offset from the center of the bumper which results in the winch cable angling to one side of the car. As the car is winched in, the cable wraps around one side of the take up spool and can become jammed. A bridle is a strap that connects to the control arms (or similar point) and allows the car to be winched from the center, thus eliminating the spooling problem.
FSR radios? These are handy for talking to your spotter when backing up. Cell phones can be used, but I find the slight lag in the audio annoying. Also, cell phones only work where there is cell service.
Insurance/Liability? Check with your insurance company about covering your trailer. It may need to be added to your auto coverage or it could be covered by your homeowner’s policy. Be sure the gross trailer weight is within the capacity of your truck or you may have an issue with insurance and liability.
Padded mats? Use these mats to kneel or lie on while you attach the tie downs under the car.
Ramps? You’ll need them for either an open trailer or an enclosed one. If you car is especially low and/or has a long overhang, you’ll need extra long ones. Race Ramps is a good place to start looking.
Rearview cameras? Pulling any car trailer greatly restricts rearview vision to the point where it may be impossible to see a vehicle following immediately behind you. One solution are sideview mirror extensions. If this does not tickle you aesthetics, then consider installing a rearview camera. These cameras are similar to backup cameras, but are on all the time. Unfortunately, I have not found one that integrates with the PCM display. The simplest setup I found was a camera attached to the back of the trailer that transmits via WiFi to an iOS or Android device. The camera is powered via the trailer’s electrical system. An old smartphone is an ideal candidate to serve as the screen and can be mounted next to your rearview mirror.. Since this device is on all the time, you will want to provide direct power to it, typically via a cigarette USB adapter.
Security? I would recommend three trailer locks: receiver lock, coupler latch lock, and coupler lock. The receiver lock secures the ball mount to the receiver. The coupler latch lock prevents the coupler from being opened, thus preventing someone from unhitching the trailer from the the truck. The coupler lock is used when the trailer is not hitched to the truck. It hinders hitching to the coupler, hopefully preventing tow away theft. If you have an enclosed trailer, then you will also need locks for the rear ramp. Finally, you can add geo tracking to your trailer. A service such as GeoSky Alert will track your trailer (or any vehicle) and notify you when it moves and when doors are opened and closed.
Tie down straps? Tie downs are used to secure the car to the trailer. They employ a ratchet system that gives you a great deal of leverage to tighten the straps. You’ll want straps designged and rated for the intended use (typically the 2” wide variety). The straps should be pretty tight, but don’t overdo it! (Whenever I can I ask “experts” to check my straps and get their opinion on how tight they should be) If the straps are new, keep in mind they can stretch a bit. Be sure to stop periodically and check that they remain secure. Also be sure that the strap goes around the spool at least two times so that it is safely secured. On my tie downs, this requires at least six full ratchet clicks to achieve this.
Tongue Jacks? This is the jack attached to the tongue used to raise and lower the tongue over the ball mount. These jacks can come with or without small wheel. Get the wheel. The jack will have a much better chance of surviving if you start to move the trailer without having lowered the jack. Trust me.
Tow hooks? Winch cables commonly attach to the car’s tow hook. You may have a hook and not even know it. These hooks are often included in the car’s toolkit. While this is the common method of attaching the cable, it is not always the best. See Bridles.
TPMS? All newer cars have tire pressure monitoring systems (TPMS), but trailers do not. The solution is an after market system often used for cars, but also well suited for trailers. These systems provide valve cap replacements that serve as TPMS transmitters and a TPMS receiver that is placed on the dashboard. The Tire Minder system I use also reports tire temperatures which can give an indication of how the load is centered in the trailer. If the rear pair of trailer tires are running hotter than the front ones, the load may be too far back, and visa versa. If you decide to purchase a TPMS system, check with the manufacturer if a signal booster is recommended (sometimes the receiver is too far away from the transmitter to get the signal without a booster). If you want your spare tire monitored, be aware that that transmitter may be different from the rolling tires’ transmitters.
Trailer dollies? Dollies are useful for maneuvering trailers in tight spaces. Manual dollies work well for lightweight trailers and motorized ones for heavier rigs. While a motorized dollies can be expensive, it may be cheaper than redesigning a parking area and certainly helps maintain matrimonial harmony.
Wheel chocks? Trailers don’t have a parking brake, so when not connected to the tow vehicle, wheel (or tire) chocks need to be used to hold the trailer in place. Chocks made of plastic have the advantage of being light, but they are prone to being blown away by high winds. This can even happen if you think they are secure, especially as I found during high winds. Here’s how. The wind buffets the trailer causing it to shimmy slightly. This can briefly release the weight on the chock and the wind sets it free.
The solution is to either use a heavier chock or secure the lightweight chock with a rope and bungee cord to keep it in place.
Wheel covers? These are used to protect your tires when parked outside for extended periods.
Winches? Winches are optional on open trailers (since you can drive the car entirely on the trailer), but are near necessities on enclosed ones where exiting the car inside the trailer may not be possible.
Hitching, Unhitching, and Parking
Basics? Attach the ball mount to the truck, raise the tongue of the trailer above the level of the ball with the tongue jack, back the truck up so that the ball is centered under the coupler of the trailer. Lower the coupler onto the ball and secure the coupler. Connect the 7 pin securely to the truck along with the break away switch cable and safety chains. To unhitch, reverse this process.
Backup cameras? These cameras in the truck make it much, much easier to backup and align the hitch under the tongue. I suspect that with practice, a good backup camera could allow the driver to complete this operation by himself/herself.
Sloping surfaces? If you have to hitch/unhitch on a slope, be sure to chock the trailer and have the truck facing uphill. This way when you unhitch, the trailer will move away from the truck as it settles into the chocks. If you must disconnect downhill, chock your trailer while still connected to the tow vehicle, place your tow vehicle in neutral and disengage all braking functions. This will pre-load your trailer against the chocks. Re-engage the tow vehicle transmission to park if applicable and re-apply the tow vehicle’s parking brake. This should minimize any trailer creep after a downhill disconnection.
Lodging? When traveling, be sure to take advantage of Google satellite map views to scope out the parking when selecting a hotel. You don’t want to arrive at your destination and find inadequate or poor parking. When checking in, I like to ask the clerk where they like to have trailers parked.
Loading, Unloading, and Preparation
Basics? With the trailer attached to the truck, raise the front of the trailer with the tongue jack (this will raise the back of the truck too, sometimes lifting the truck’s rear wheels), and deploy the trailer’s ramps along with any car additional ramps. For an open trailer and some enclosed ones, you may now slowly drive the car onto/into the trailer. To unload, reverse the process.
Winching? For some enclosed trailers, the car will have to be winched in. Attach the winch hook to the car’s tow hook or, better yet, to a bridle. Take in any slack in the cable, release the car’s parking brake and put it in neutral. Try to winch the car in using one continuous pull. This will keep tension on the cable and avoid tangling. I have found it difficult to load the car in one pull, so I hold the cable using heavy duty gloves and always make sure there is tension on it. I can also help guide the cable into the winch such that the cable is distributed evenly on the spool. Of course, focusing too much on the winch can take your attention away from the car, so be careful and take your time.
Trailer angle? The above winch process only works if the trailer is sloping down slightly from the front. The trailer’s jack is used to set the slope. This angle can be as little as 3-4 degrees. An easy way to consistently achieve this angle is to open that oft used compass app on your smart phone. You probably didn’t realize it, but it also includes a level feature. Lay the phone on the tongue and adjust the trailer jack accordingly.
Mirrors? You may want to retract the sport car’s mirrors.
Antennas? Remember to lower or remove roof mounted antennas when loading a car into an enclosed trailer.
Parking brake? Once the car is positioned on or in the trailer, engage the parking brake.
Manual transmissions? Do not leave the car in gear. If left in gear, the constant shifting of the car would move the pistons in the cylinders without lubrication. Not a good thing.
PDK? Leave the car in park. In an enclosed trailer, this can be a challenge as you may be forced to do this from the outside with the engine on and the brake pedal being pressed. This contortion will require leaning in the window with some sort of stick to engage the brake pedal in one hand while the other hand moves the gear lever. Be sure to practice this!
Tie down methods? The most common technique is to secure the tie downs to the car’s wheels. The tie downs don’t attach directly to the wheel. Instead, axle straps are fed through the wheels the tie downs attach to the straps. Axle straps come is various sizes and you will want 40” or 44” lengths. Not surprisingly, axle straps can be used on axles (not recommended on Porsches) as well as any accessible areas of the frame. Another option are straps that go over the tops of the tires. This usually requires a rail system to anchor the straps to and is useful for cars that have very low ground clearance. The last option is to install tie down anchor points underneath the car. Rennline offers several Porsche specific ones. I use this method on my Mini Cooper and it works quite well.
Tie down patterns? Once attached to the vehicle, route the straps to the nearest anchor point (unless you are cross strapping). This pattern works well if the anchor points are 2 feet or more from the tires. If the tire is too close to the anchor point, then the strap may have to be secured to the nearest anchor point on the other side of the trailer. Doing this with both front and/or rear tires creates an “X” pattern with the straps crossing over one another. The pattern used on the front does not have to match the pattern used on the back.
Take the keys out of the ignition? It is easy to forget that you’ve left the key in the ignition in the Accessory or On position to unlock the steering wheel while loading the car. Remember to remove the key or you may wind up with a dead battery upon reaching your destination.
Trailer tire pressures? Recommended tire pressures should be displayed somewhere near the front of the trailer, usually on the driver side. The information should be displayed in a similar fashion as what you see on your car’s tire pressure information posted in the driver’s door jam.
Car tire pressures? Keep in mind the tire pressures of the sports car. If you load the car in fresh off the track when the tire temperatures are high. guess what will happen in an hour or two? The tires cool and the pressures drop. This could loosen the tie downs. Dramatic elevation changes could have the same affect. Under these circumstance, be sure to check your tie down tensions periodically.
Truck tire pressures? Some vehicles have two sets of tire pressure recommendations: one for unloaded and another for loaded (e.g the Cayenne). Check your truck’s manual.
Loading the trailer without the tow vehicle attached? This can be done, but do so carefully. The key is to place jack stands under the back edge of the trailer at a structurally strong location and then use the tongue jack to raise the front of the trailer and load the jack stands. Even with the trailer’s wheels chocked, the main concern is that when loading the trailer the momentum of the car rocks the trailer and knock it off the jack stands. Unlike conventional jack stands, Jackpoint Jackstands are much wider and more stable – perfect for this application.
Wide turns? The sharper the turn, the more the trailer’s inside wheels will cut inside of truck’s wheels. So when turning right at an intersection, you’ll want to initially go straight and then turn right. This will keep the trailer’s wheels from hitting the corner of the curb.
Jackknifing? Be careful not to turn so sharply that the tongue of the trailer will hit the bumper, especially in reverse.
Longer braking distances? Be sure to allow much more distance for braking. You’re probably carrying twice the weight as you are used to.
Stay in the center of the lane? You’re also wider than you are used to, so pay more attention to keeping the truck centered in the lane. When lack of traffic allows, let your truck drift to each side of the late and note when the trailer’s tires hit the dots or rumble strips so you can better gauge your position in the lane.
Check those tie downs? It is a good idea to stop occasionally and check the tension on your tie downs. Changing temperatures and elevations can affect your car’s tires, which, in turn, affects the tie downs’ tensions.
Wind? Slow down when first driving in windy condition and see how the wind affects your trailer. The taller and boxier the trailer, the more adversely it will be affected by the wind.
Elevation changes? As you climb, the truck’s towing capacity degrades. Remember, the stated towing capacity is at sea level. For Cayennes, the loss is 10% per 1000 meters. This is in the same ballpark as what I have read elsewhere for other vehicles: 2% per 1000 feet. Check your tow vehicle’s manual as these figures can vary.
Route options? If you have options on which routes to take, give more weight to the route with less elevation change. Hills and mountains adversely impact fuel economy.
Calibrating your brake controller? Your brake controller’s manual will describe the proper procedure. For the Prodigy P3, this means driving on a flat surface at 25 mph and adjusting the gain on the controller until the trailer’s tires skid when the brakes are applied, then adjust the gain down slightly. Different settings are required when the trailer is empty or loaded at a different weight. If you can’t get the tires to skid like I did, you want to adjust the gain so that the trailer slows at the same or slightly greater rate than the truck. If it feels like the trailer is tugging slightly when you brake, this is fine.
Practice? Find a large open parking lot and practice. Then practice some more.
Spotter? A spotter or assistant is your best friend. Use FSR radios or the equivalent to communicate with the spotter. Ask the spotter to keep an eye on both sides of the trailer and truck. When turning tightly, have them check for jackknifing. Never raise your voice when speaking to the spotter. Be patient.
Steering? One helpful tip is to hold the steering wheel at the bottom and move it in the direction you want to go.
Brake controller? You’ll probably want to disengage the brake controller when backing up. Check the manual on how to do this.
Maintenance and More
Torque lug nuts? Check the torque on the trailer’s lug nuts after the first 100 miles (if new) and then per manufacturer’s recommended torque check frequency (expect about every 1,000 miles). See your trailer’s manual for the appropriate torque value, but expect it to be in the 90-120 ft/lb range.
Lubricate axles? Check with the trailer’s manufacturer. This may also vary with the weight cars you transport, with heavier cars resulting in more frequent inspection and lubrication.
VIN number? The trailer’s VIN number is usually on the driver side of the tongue.
Autonomous Trucks? In a few years you may not need your own truck. Instead you’ll hire an autonomous truck to take your trailer to it’s destination. And if you don’t need the security of an enclosed trailer at the destination, perhaps you will no longer need a trailer. We’ll have to wait and see.
Special thanks to Damien Federlin of Aerovault Trailers for proofreading and contributing to this article.