A tri-fold tonneau truck cover Tonneau covers are hard truck bed covers that protect your truck and the items you carry in it. But why should you have one? Truthfully, the answer is found in simple science and economics. Trucks are not very aerodynamic, so wind is sucked down into the bed when driving, which causes drag. Installing a truck bed cover eliminates the drag and can result in better gas mileage. In some cases, the cover may pay for itself in as little as a year with the money you'll save on fuel! Some other benefits are keeping your cargo secure. First, the cover will keep things from being blown out onto the road and preventing accidents or accidental littering. They also keep undesirable debris, snow, and rain out of your truck bed and off of your cargo. While no truck bed cover is completely waterproof, they are highly effective at protecting your cargo from the elements. Tonneau covers also keep your cargo a complete mystery. Some even come with locking mec...