September 27, 2005

How to choose a tow vehicle
By Jeremy Cato

If you are shopping for a tow vehicle, keep in mind that most dealers won't let you hook up your trailer and go for a test drive. So you'll need to base your decision on answers to these questions, including an evaluation of vehicle specs, rated towing capacity and driving impressions of the vehicle without a load hooked up behind. Most vehicles designed for serious towing also are available with more than one engine and transmission choice, as well as different suspension options, comfort and luxury features, and two- or four-wheel drive.

Here are some questions to help guide your decision-making:

1. What is the vehicle's Gross Vehicle Weight Rating (GVWR) and towing capacity? The GVWR is the maximum permissible weight of everything on and in your vehicle -- including the vehicle itself, passengers, cargo, and fuel. What is the weight of all your vacation gear, passengers, and luggage? Add that to the weight of the vehicle itself and if you are approaching the maximum GVWR while towing near the maximum towing weight, you need a vehicle with more capacity.

2. What's the weight of your trailer? Many trailers display this or include it in a manual. If you can't find the number, go to a truck stop and weigh the trailer section.

3. Which vehicle? Car, pickup or SUV? If you are towing something big and heavy, a large pickup driven by diesel engine with a highly-rated towing package is the best choice, by far. If the tow load is 500-1,000 kg, a smaller vehicle might be just fine. Check with the vehicle's tow rating.

4. Are vehicles with car-like unit-body construction okay for towing? Depends on the weight of the trailer. Full-frame vehicles and traditional trucks are the best choice for pulling heavy loads because the tow hitch can be attached directly to the frame with full-frame vehicles. For lighter trailers, a unit-body vehicle can be adequate. Check the tow ratings and stay on the cautious side.

5. Front-, rear-, all-, or four-wheel-drive? Rear-drive is the best choice for towing, but certainly not the only one. Compared to front-wheel drive, rear drive offers superior traction and stability. All-wheel-drive vehicles sometimes offer traction help for towing but there is sometimes the danger of added wear and even damage occurring in towing. Before buying a new vehicle, check on warranty considerations when towing with an AWD vehicle. Vehicles with truck-style part-time four-wheel drive are heavier than rear-drivers and you should never engage a part-time four-wheel system when towing.

6. Automatic or manual transmission? Automatics are easier for less experienced drivers who might have difficulty with a manual gearbox driving a heavy load attached at a hitch.

7. Which engine? Look for torque not horsepower. Diesels excel at towing because of their excellent torque characteristics and superior fuel economy. Diesels are also more durable but also more pricey.

8. What sort of tow package should I get? The special towing package with an oil cooler, transmission fluid cooler, heavy-duty alternator and battery, higher-capacity rear springs, and possibly a stabilizer bar (or larger one than standard). Trucks might also get a lower final drive ratio (a higher number means lower gearing - desirable for towing) and heavy-duty differential.

9. Which hitch? There are three different types of hitches: Class 1 (up to 907 kg), Class II (up to 1,587 kg), and Class III (up to 4,536 kg). You want the highest rated hitch possible in case you plan to tow a heavier trailer or a second watercraft. As for hitch installation, this is not a job for even the most competent do-it-yourselfer. Find a skilled custom hitch installer and let them do the work. This is especially important for front-drive vehicles and any vehicle with modern unit-body construction that lacks a traditional ladder frame. Most passenger cars and many minivans and small sport-utility vehicles have unit-body construction.

Towing add-ons

1. Transmission oil coolers. If you tow loads of more than 454 kg for more than an hour you will need a transmission oil cooler. Most manufacturers include them with a standard trailer tow package. If not, get one installed to protect your transmission from boiling.

2. If you are concerned about brakes overheating, there are dash-mounted devices that display information from sensors mounted on the brake at each wheel. They warn that the brakes could be on the verge of overheating and fading.

3. A coupler lock secures the coupler socket, preventing thieves from pulling up and towing your trailer away when your vehicle is unhitched.

4. The fifth-wheel option: a fifth-wheel hitch is positioned in the bed of a full-size pickup is often ideal for those pulling larger trailers. The beauty of a fifth-wheel is that it eliminates many of the weight balance and hitch geometry problems of a ball-and-coupler hitch

Jeremy Cato is an award-winning print and broadcast journalist. He is a columnist and feature writer for the Globe & Mail newspaper and his articles are syndicated to a variety of other publications.