Roof boxes are a convenient solution for transporting extra luggage, especially during winter trips.
However, while they offer additional storage space, they also impact fuel efficiency. The increased air resistance can lead to higher fuel consumption, making it essential to understand how speed influences overall costs.
Testing the Fuel Impact of a Roof Box
A recent test, reported by Autokult, examined how much more fuel a car consumes when equipped with a roof box.
The test was conducted on a highway using a Jeep Compass 4xe plug-in hybrid with a 196 cm-long Thule roof box attached. To ensure accurate results, the vehicle was tested at different speeds while maintaining consistent driving conditions.
How Speed Affects Fuel Consumption
The results showed that driving with a roof box increases fuel consumption by 10 to 17.5%, depending on speed. The higher the speed, the greater the difference.
Interestingly, at speeds between 90-110 km/h, the increase in fuel consumption remained relatively stable. However, beyond this range, fuel usage surged significantly.
Optimizing Fuel Efficiency
While it’s impossible to completely avoid the extra fuel costs of a roof box, reducing speed can make a noticeable difference.
By maintaining moderate speeds, drivers can minimize the financial impact of using a roof box while still benefiting from the added storage space. When planning a long trip, balancing speed with fuel efficiency could lead to significant savings over time.
