TOPIC: Choosing a Tow Vehicle
INSTRUCTOR: Alan Cohoe
Tow vehicle choices have increased. No longer just Ford and Chevy; now you can also choose long or short bed trucks, different makes and models. But weight considerations are still a primary issue all through North America -- the U.S. and Canada alike.
The Gross Vehicle Weight Rating, (GWVR) is the maximum weight that the design of the RV can carry. This rating can be changed by the manufacturer or by an expert, who will find the weakest part of your RV and attempt to make that weak link stronger. Although some trucks can carry more weight than others, generally a 1/2 ton truck can carry 1,000 lbs., a 3/4 ton truck 1,500 lbs. and a 1 ton truck, 2,000 lbs. It is very important to know the GWVR of your vehicle.
The Gross Axle Weight Rating (GAWR) is the amount of weight that each of the front and rear axles of the truck can carry. This total is what the vehicle is designed to carry. Period. It is not an average. The total of the front and rear axles will not equal the GWVR, but will exceed it. The GWVR is of major concern, but cannot exceed the GAWR.
Your tires must be equal to the job. Each of your front tires must carry at least half the weight required by the front axle. Each of your rear tires must carry half (or, in the case of dual tires, one quarter) of the weight required by the back. Be aware that when you change tires, or add on special weight equalizing equipment, it will not change what the truck can carry.
The weight on the truck box at the rear axle is especially important for a 5th wheel or camper. Weigh your truck, empty, on a commercial scale. (In Canada, these scales are open 24 hours a day, so you can weigh in off peak times to avoid the commercial traffic). After weighing the empty vehicle, weigh the trailer, camper, etc. full of what you would normally put in it.
The 5th wheel needs 15 - 20% of its total weight on its tongue to tow in a stable manner. That figure is 10-12% for a trailer. Otherwise there is danger that, when trying to stop, you will jackknife.
Other choices you will have to make when choosing a tow vehicle include: the engine, whether gas or diesel. How much will it cost, how long do you plan to keep it? The transmission, should it be standard or automatic? An automatic should be equipped with a transmission cooler and a temperature gauge. This will keep the transmission fluid at the correct temperature, neither too hot nor too cool. 250 degrees when traveling, 300 for very short duration spurts, such as when you are almost at the top of that hill, and never under 100 degrees, when the lubricant will deteriorate.
The rear end axle ratio determines how well the vehicle will pull. At 2.56, you will get great mileage, but very poor pulling performance. The other end of the scale, 4.50, is strictly for pulling. Somewhere around 3.50 to 4.10 is the recommended range. If you have the wrong axle ratio, this can be changed.
Other considerations include: 2 or 4 wheel drive. 4wd is costlier, but has a higher resale value, as it is currently the "in" thing. If all you are going to do is to tow a large 5th wheel or trailer, the medium duty truck is definitely the way to go.