Do tonneau covers really improve gas mileage ?
Truck owners often have their own theories on how to improve gas mileage and reduce the air drag on their pickup trucks. One simple solution is to lower the tailgate. Another is to replace the tailgate with a cargo net. Bed caps or tonneau covers can be added as well. According to the Federal Chamber of Automotive Industries, while sales of passenger vehicles in July 2004 were down 9.2% vs. July 2003, sales of SUVs and light trucks increased 1.2% and 4.2%, respectively. With the desire to own pickup trucks combined with high gas prices, it seems as though more studies on how to decrease drag should be conducted. In the simplest terms, drag deals with resistance to airflow. Cars and trucks alike experience drag. The drag coefficient, Cd, is usually determined experimentally—the lower the value of Cd, the better. The most important thing for the average car or truck owner to know is that the larger the value of Cd, the more work the automobile has to do to push against the air it drives
