DO ROOF BOXES REDUCE FUEL ECONOMY?

A roof box does change the airflow over a car and as such, it will have a very small impact on your fuel economy. As the vehicle will essentially become larger, there is more wind resistance and due to this the car will have a slightly reduced amount of miles per gallon – this is known as “drag”.

As well as the additional wind resistance, the roof box will allow you to carry more weight due to the belongings inside it. Both of these combined will cause your engine to work a little bit harder to move the car as normal.

Does that mean your fuel consumption will go up massively? Well according to most manufacturers, fuel consumption will not dramatically increase. Yes it will go up slightly due to the additional drag and weight but not significantly enough for you to notice much difference.

When speaking to Thule who are one of the biggest and most advanced on the market, they estimate that you should see no more than 5% increase in your fuel consumption with a roof box attached.

You will notice nearly all roof boxes are a strange shape, this is by design to help the roof box cut through the air resistance and reduce drag – you will notice the front section is usually flatter – like a wedge shape – and this means a smoother air flow over the car.

To order your Roof Boxes or if you have any questions, you can Contact Us and we will be more than happy to help.