Environmental awareness, fuel-efficient driving and noise reduction with a trailer
Why a trailer costs fuel
Aerodynamic drag rises with the square of speed, so towing at 100 km/h instead of 80 km/h can add a quarter or more to fuel consumption. Extra mass also means more energy on every acceleration and more heat in tyres and brakes.
Eco-driving a combination
- Accelerate smoothly and reach the highest sensible gear quickly; keep revs low.
- Anticipate: lift off early for junctions, tolls and descents and let the combination roll.
- Check tyre pressures on car and trailer when cold - soft tyres raise rolling resistance and temperature.
- Switch off the engine during longer stationary waits rather than idling.
- Strip unnecessary load and remove roof boxes and empty water tanks.
- Plan the route for fewer stops, gentler gradients and less stop-start traffic.
Noise
- Worn or under-inflated trailer tyres howl; worn brake shoes squeal - both are noise and safety issues.
- Avoid revving and unnecessary horn use near housing; drive more slowly and smoothly at night.
- Secure loose items: rattling loads are a nuisance and can shift.
Worked example
Two identical 300 km trips: one at 100 km/h using 11 L/100 km, one at 85 km/h using 9 L/100 km. That is 33 L against 27 L - 6 L saved, roughly 10 EUR at 1.60 EUR/L, plus less tyre and brake wear.
Traps that cost marks
Treating the trailer as free once rolling; ignoring trailer tyre pressures; over-revving on climbs instead of changing down early; assuming eco-driving means crawling and holding up traffic.