Roof load and roof box - rules, weight and driving behavior
Roof loads and roof boxes can be practical, but they affect the car’s aerodynamics, centre of gravity and braking distance. Correct mounting and moderate speed are crucial for safety.
Weight limits and placement
| Component | Typical limit | Tips |
|---|---|---|
| Total roof load | 50–75 kg | Check the registration document and the manufacturer’s roof rating |
| Roof rack | Follow manufacturer | Inspect bolts before every trip |
| Roof box | Follow manufacturer | Spread the weight evenly, keep heavy items low and centred |
Related rules: Weight concepts for passenger cars and Rules for tires and chains .
Securing the load
- Use straps through the roof box anchor points
- Secure everything inside to stop shifting under braking
- Check locks and hinges before departure and during breaks
See also Securing loads and passengers .
Impact on driving characteristics
| Condition | Effect | Action |
|---|---|---|
| Higher centre of gravity | More body roll in curves | Reduce speed in bends, keep steering smooth |
| Increased drag | Higher consumption and noise | Slow down, remove the box when not in use |
| Wind sensitivity | Crosswinds disturb the course | Keep distance, prepare at tunnel exits and bridges |
For more about wind effects, see Crosswind and gusts .
Recommended driving pattern
- Reduce speed, especially above 80 km/h
- Increase following distance and brake earlier
- Avoid sudden evasive moves and lane changes
- Recheck the attachments on longer journeys
Checklist before departure
- Roof rack correctly mounted and tightened
- Box/straps properly fastened and locked
- Load distributed and secured against movement
- Tyre pressure adjusted for the load, see Tyres and maintenance
Summary
Roof loads and roof boxes demand precise weight management, solid fastening and an adjusted driving style. Reduce speed, keep distance and secure the load to drive safely and predictably.