Roof Load
Roof load is the maximum mass permitted on a vehicle's roof while driving. It normally includes the roof rack, crossbars, mounting hardware, and the carried item.
Use the lowest applicable limit
The vehicle roof, rails, rack system, and accessory mounts may have different ratings. The usable limit is the lowest applicable value after the carrier's own mass is included. A panoramic glass roof or factory rails do not by themselves establish a particular capacity.
The published roof-load figure is usually a dynamic limit for a moving vehicle. A manufacturer may state a separate static limit for a parked vehicle or roof tent, but a higher stationary rating must not be treated as permission to drive with that mass. Check the instructions for both the vehicle and the carrier.
Roof cargo raises the centre of gravity and can affect handling, braking, height clearance, wind noise, and energy consumption. Large boxes or equipment can reduce EV range through aerodynamic drag even when their mass is modest. For equipment choices and loading checks, see Roof Cargo.