Pros and Cons of installing a roof box or roof rack on your car

A roof box is handy for increasing storage space in in your car. You can install a roof box on your car by yourself, or you can get the shop to do it for you.

If you're planning to install a roof box, there are several types of factory-fitted roof mounts:

• raised rails
• solid-type rails
• fixed mounting points
• no mounting points

Some cars come with roof rack mounting points, while some don’t. Having factory-fitted mounting points makes installing the roof box easier. Not having them just means you need roof bars that clamp onto your door frame.

Whatever the mounting point type is on your car, make sure the roof box and roof bars are securely fastened.

You have to check your owner’s manual to find out how much weight your roof can handle. For example, the 2020 Honda CR-V can take up to 75kg on the roof (including weight of roof box and roof bars).

Some car models don’t have this explicitly mentioned in the owner’s manual, but it should be typically around 60-75kg only. Fill the roof box with large but light items to make full use of it. Put heavy loads inside your car first.

There is a speed limit too, but it's usually around 90mph or 140km/h, which is beyond the speed limit anyway.

While handy, the roof box has its own set of pros and cons.

Pro – Additional space without additional foot print

Usually, we opt for bigger cars if we want to carry more load. For most of us, we only need the extra luggage space occasionally (balik kampung), and our large cars with large cargo spaces are usually under-utilized in our daily commute.

Having a roof box makes this unutilized space removable and enables us to drive a smaller or sportier car for daily purposes. Need more space? Put the roof box on. Don’t need space? Take it off.

In other countries, drivers even opt for luggage trailers to haul more stuff around. The average parking space does not accommodate a trailer; hence the roof box is a much more practical option.

Con – Increases fuel consumption

The roof box increases the frontal area of your car (more surface area hitting the wind). Some roof boxes are more aerodynamic than others, so take your time browsing your options before you make a purchase. No matter how aero a roof box is, it will still negatively affect the aero of your car.

Pro – Good distribution of weight

Depending on your car, the weight that the roof can take will vary. A Honda CR-V, for example, can take 75kg (including weight of roof box and roof bars).

When we say a good distribution of weight, we are comparing the roof box against rear cargo boxes that you hitch at the back of your car.

The roof boxes weight is distributed to the A, B, and C pillars, and all four tyres. In contrast, a rear cargo box puts more weight on the rear wheels.

Con – Additional height

If you’ve installed a roof box (or roof rack), you might want to check the new total height of your car. You might not be able to pass low height limit entrances anymore. Check in advance (and remind yourself while driving) to avoid catastrophic embarrassment.

So, installing a roof box on your car isn’t such a bad idea. It’s handy for the occasional road trips and you can uninstall it when not in use. The pros and cons are pretty balanced and there are various options to choose from. Just make sure to install them properly and to not exceed the weight limit.