Best Position for A Roof Box on A Car

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Whether you're going on holiday or taking a day trip to your favorite fishing lake, a roof box can provide you with that much-needed additional storage room. However, without getting it fitted by a professional, how do you know the best position for a roof box on a car? Below we find out:

The best position for a roof cargo box is the crossbars' central point, with the narrowest end of the box facing the front. However, having your cargo box in the center isn't a must. If you'd like to position your cargo box slightly to the left or right of the central point, that's also okay. But installing a roof box this way will affect the vehicle's weight distribution. Therefore, you may need to store something else to even this out.

As you can see, the best position for a roof box is the central area of the crossbars, with the most pointed end facing the front. Although it isn't a requirement to place the roof box in the center, positioning the box with the narrowest part facing forward is. This comes down to aerodynamics, and it'll provide you with a much more unrestricted trip.

How to properly install a roof box on a car

Now you understand the best position for a roof box on a car, let's discuss how you can achieve this. Below we detail a complete how-to guide from the equipment needed all the way to the installation process.


Before we get into the installation process, let's talk about the equipment needed to secure a roof cargo box to your car successfully. The list isn't extensive and mostly all self-explanatory, so let's see what's required:

  • Roof rails (isn't a requirement) – First, you may or may not need roof rails installed on your vehicle, which will depend on your car and crossbar choice. If you have roof rails already installed onto your car, great, you'll need standard crossbars, which are more suitable for the application. However, if you haven't, you can either purchase non-roof rail crossbars, or install roof rails to equip the standard crossbars. This is highly dependent on your decision, but either way will work superbly.
  • Crossbars – Briefly mentioned above are crossbars, and these are a requirement for all roof boxes. These are what secure the box to the roof. However, you primary get two different options: with roof rails and without roof rails. Either will work superbly, and it'll depend on whether you have roof rails or not.
  • Cargo box – Of course, you'll need the cargo box. There's an abundance of these sold within the industry. Because of this, we highly recommend you take a look at this post. Here we go into detail about the top 5 hardshell cargo boxes that are currently on the market.
  • Tools – The tools you'll need will vary depending on the roof rails, crossbars, and cargo box you invest in. Mostly all cargo boxes are toolless to install, but you'll always want tools nearby for the roof rails and crossbars.

The above is all the equipment needed to install a roof box. Once you've gathered these, you're now ready to start the installation process. To begin this, follow the below step-by-step guide carefully.

Position for A Roof Box on A Car


While installing a rooftop cargo box it's beneficial to have two people. It dramatically helps with all the awkward lifting and positioning. Once you've got a helping hand, follow the below steps:

  • Fit the crossbars – Before loading the cargo box on your rooftop, you'll need to install some crossbars. Depending on which crossbars you purchased, it will vary on how you equip them for your car. However, for a rough guide, you'll want to either attach your crossbars to your roof rails and tighten, or open your doors and connect the crossbars to your door's archway.
  • Load the cargo boxNow you've fitted your crossbars, it's time to load the cargo box. Mostly all roof boxes are large and are awkward to lift with one person. Therefore, the second pair of hands may be needed during this stage. Once you have some help, lift the cargo box onto the car's roof and centralize it, ensuring the narrowest part of the box is facing forward. When you're happy with the box's position, it's time to secure it to the crossbars.
  • Secure the roof boxUse the supplied key to open the cargo box and search for the tightening knobs (there are usually four of these at each corner of the roof box). Start turning these right to tighten the external clamps onto the crossbar. While you're doing this, get the second person to look at the clamps to see if they're connecting to the crossbar correctly. If not, maneuver the box into a position where the clamps can attach themselves to the crossbars.
  • Re-evaluate installation – Once you're happy you've tightened up all the connection clamps onto your crossbars, you'll want to re-evaluate the installation to ensure it's successfully installed. Double-check the connections, rock the box side to side to check for movement, and wiggle both crossbars to ensure they're secured well.

As you can see, installing a cargo roof box is relatively straightforward. However, installation methods may differ depending on the brand. Therefore, only use the above as a rough outline. Always follow the instructions provided by the manufacturer of the roof rails, crossbars, and cargo boxes.

Things to consider before loading your roof box

Now you can install a cargo roof box successfully. Here are some essential tips you'll want to remember before loading anything inside. By implementing these considerations it will dramatically decrease the chances of any drastic issues.

  • Recommended max load weight of the box – all rooftop cargo boxes will have a recommended maximum weight. Going over this highly increases the chances of your box breaking and being a hazard to yourself or other road users.
  • The maximum load weight of the car's roof – additionally to the above, you'll also want to become knowledgeable on the recommended max weight limit for your car's roof. The last thing you'll want to encounter is damaging the structural integrity of your vehicle. When calculating this, be sure to include the roof rails, crossbars, cargo box, and the actual load into the weight.
  • If the roof box is fitted correctly – this sounds obvious, but many people forget from time to time. Before traveling with your cargo box, ensure it's fitted correctly. For example, check if the clamps are secure, the box is centralized, and if the connection on the crossbars is okay. Just a simple five-minute check over is more than enough to guarantee your roof box is fitted appropriately.

About the author 

Vieira Babeker

Hi! I'm Vieira. I've always been interested in different Auto Accessories

My passion here at is to provide helpful straight forward clear advice and tips for Automotive Accessories.

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