Tuesday, January 17, 2012

Why do Vehicles Have Tow Ratings


We have all seen the truck commercials with bold claims and flashing graphics but what are they all getting at. What is all this towing of huge boats up hills and pulling stumps out of the ground? Well this is not to show the diesel fuel pump or diesel injectors are working, no this is to give an idea of what the truck can haul. Most commercials show a “Do Not Attempt” warning to keep people from destroying the truck once they buy it. The fact of the matter is that trucks can really only haul a specific kind of weight at very specific speeds.

Most trucks have a towing rating that can handle towing a car or truck behind it but what are the dangers of going over the tow rating? First off is the danger of extended braking distance, while some trailers have their own braking system most use free spinning wheels. The added weight of the trailer means more work for the brake system to handle and that translates to greater stopping distance. This means that the driver must think differently then he normally would. Also it means that the brakes will heat up and begin to “fade” faster. Brake fade is when the heat cannot be dissipated and the pads become molten. When this happens the braking ability drops to almost zero.

The next huge issue for towing capacity is what the frame of the truck can handle the added weight. Now must trucks are built with a very sturdy frame that can handle a good 10,000lbs more than the trucks weight. When this weight is increased the stress on the “back bone” of the vehicle can be pushed past its rating. Exceeding the rating can cause the frame of the vehicle to bend or even break.

The ratings given by the manufacturer are there for a reason and they do give a bit of flexibility but should never be exceeded. There are many other issues that can arise when the tow rating is exceeded which can not only be dangerous but also kill your gas mileage!

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