Tonneau covers (pronounced ta'-no) are used to cap the beds of pickup trucks providing a rigid lid that can be locked into place. They are handy for securing cargo and for keeping the bed free of leaves, weather-wear and debris.
Tonneau covers come in a variety of styles and price ranges. Many install without drilling by using clamp-on systems allowing for easy removal. Simple models provide basic security and protect the bed, but are less flexible in design. To gain wide access to the bed, the cover might need to be removed.
Other tonneau covers are designed to be raised from the back, much like an engine hood. This allows greater access to the bed and also the ability to carry longer cargo over a closed tailgate. Four-way tonneau covers are made so that the back, front or either side of the cover can be raised, allowing more convenience. There are also two and four-panel covers that are sectional rather than solid for a different type of accessibility.
Most tonneau covers are weather-resistant, extending the life of the bed of the truck by helping to prevent rust. In an unprotected bed, water can accumulate under non-spray liners, leading to body rot. By sealing the bed off from the elements, the body of the truck benefits too. Pickups might also show improved gas mileage from reduced aerodynamic drag.
Aside from securing cargo and discouraging or even preventing bed rust, tonneau covers can add to the style of a truck. Fiberglass covers can be painted to match vehicle color, while black tonneau covers match the trim of the truck.
Tonneau covers vary widely in weight depending on size and construction material. For example a fiberglass cover can weigh 125 pounds (57 kilograms), while a cover made of hard shell plastics can be closer to 35 pounds (16 kilograms). Some of the lighter tonneau covers come with additional hardware so that the lid can be hung on a garage wall to store it out of the way. The advantage of the latter type is that one person can remove it without assistance.
For some, the idea of a rigid bed cap that has to be removed to haul larger items might sound inconvenient. In this case there are rollaway tonneau covers. These are constructed with rigid slats of plastic that roll up into a canister. The canister is installed at the head of the bed under the back window and a pull strap is used to slide open the cover along side rails. The cover locks into place at the tailgate. With a rollaway cover, if you make an unplanned stop at the local home improvement center, you won't find yourself wishing you had removed your topper before leaving the house.
If you occasionally use the truck with a camper shell, slide-in camper, or 5th wheel, ask which tonneau covers will accommodate this. In most cases the hardware is unobtrusive but each model is different so be ready with your clearance measurements when you begin shopping around. Those with 5th wheels may prefer a sectional style tonneau; in the end however, there are many choices for nearly everyone.