What Is a Rocker Panel on an Automobile?by Hunkar OzyasarUpdated June 08, 2023
The rocker panel is the lowest body panel on the side of the car located between the two wheelwells. In most cars, only the edge of the rocker panel is visible when the doors are closed since it supports the bottom of the door. The rocker panel can feature the manufacturer's logo and is usually polished for aesthetic appeal. In light trucks, it can also work as a step to facilitate easier entry into the vehicle.
The rocker panel is located along the side of the automobile; most of it is hidden under the door when the door is closed. The rocker panel is the outer edge of the car's underbody and provides structural support to the vehicle. It also supports the door, since the door rests on the rocker panel, while closed. If you have ever driven for many hours with an elbow pushing against the door, you should thank the rocker panel of your car for the support.
Earlier cars, especially heavier models from the 1930s and 1940s, had a tendency to bend in the middle in front end collisions. Since two or four holes must be cut out from the body in a typical automobile--to make space for the doors to fit into--engineers have a hard time building sufficient structural rigidity. The rocker panel plays an important role here as it resists the crumpling of the structure and lends support to the underbody of the vehicle.
Due to its location, the rocker panel is not covered by the carpet or leather that lines most interior surfaces of a car; it therefore has a shiny, polished surface. It is often used to maximize the visual appeal of the vehicle, and interior designers like to place the logo of the manufacturer or spell out the car's model name on the rocker panel. Some aftermarket rocker panels are illuminated for further visual impact.
The rocker panel can be accessed easily by simply opening the door. It is not hidden under many layers of covers, equipment and wiring as most of the car's components are and is therefore easy to change. Both to visually customize a vehicle and to replace the old, rusty or worn original, rocker panels are one of the favorite pieces for enthusiasts to replace in their own garage.
In trucks and SUVs, the rocker panel is often used as a step for easy access into the vehicle. As trucks and SUVs are relatively high, this added step makes the process of entering the vehicle easier. To support the weight of occupants thousands of times during the life of the vehicle, the rocker panels on these larger models are bigger and sturdier.
Hunkar Ozyasar is the former high-yield bond strategist for Deutsche Bank. He has been quoted in publications including "Financial Times" and the "Wall Street Journal." His book, "When Time Management Fails," is published in 12 countries while Ozyasar’s finance articles are featured on Nikkei, Japan’s premier financial news service. He holds a Master of Business Administration from Kellogg Graduate School.