A supplemental assembly, often retrofitted to semi-trailers, allows for raising or lowering one or more axles to adapt to varying load requirements. This modification enhances maneuverability, reduces tire wear when empty or lightly loaded, and complies with certain road regulations regarding axle weight distribution. These systems commonly employ pneumatic or hydraulic actuators to lift the specified axle clear of the road surface.
The principal advantage lies in optimizing operational efficiency and minimizing costs. By lifting an axle when carrying less weight, operators experience improved fuel economy and reduced wear on tires and suspension components. Furthermore, adherence to legal weight limits across different jurisdictions becomes more manageable, mitigating the risk of fines and delays. Historically, these additions have evolved alongside advancements in trucking technology and regulatory demands for greater load control and road preservation.