Environment, energy-efficient driving and vehicle loading
This domain links fuel and emissions to concrete driving habits, and adds the loading rules that affect handling and legality. Swiss questions are practical: which gear, when to switch off, what a roof box costs, and when a load makes the car unsafe or illegal.
Energy-efficient driving
- Accelerate briskly but shift up early, around 2,000 rpm in a petrol car and a little earlier in a diesel.
- Look far ahead and use engine braking instead of late, hard braking; smoothness saves more fuel than slow acceleration.
- Switch the engine off for longer waits such as a closed level crossing or a long red light; idling burns fuel and is banned where it is avoidable.
- Keep tyres at the correct pressure, remove unused roof racks and boxes, and use air conditioning sparingly.
- Fuel use rises with the square of speed through air resistance - 120 km/h uses far more than 100 km/h.
- Regular servicing, the correct oil and a working catalytic converter cut consumption and emissions; noise is pollution too.
Loading
- Stay within the permissible total weight, the axle loads and the roof load given in the vehicle documents and manual.
- Load low and centred over the rear axle; heavy items at the bottom.
- Secure everything: an unsecured load becomes a projectile in an emergency stop.
- Nothing may block your view, the lights, the mirrors or the number plate; passengers only in seats with belts.
- A heavy load or trailer changes handling and braking: adjust tyre pressure, headlight aim and your speed. Trailers need a correct nose weight and must not sway.
Worked example
Five adults, a full boot and a 60 kg roof box on a car with a 400 kg payload allowance. Adding passengers and luggage brings the total to roughly 430 kg, over the limit. The car sits low at the rear, the headlights point up, braking distances grow and the roof box adds drag and lift. The legal and safe answer is to remove weight from the car, check the axle load, and confirm the roof load limit - often only 50–75 kg including the bars.
Traps that cost marks
- Thinking a heavy load only affects fuel consumption.
- Leaving an empty roof box fitted "because it is empty".
- Forgetting the payload when five passengers get in.
- Securing a load with the rear seats folded but no straps.
- Letting the engine idle for minutes while waiting.