Rooftop Cargo Box on Car

How to Choose a Roof Cargo Box: The Ultimate Guide and Best Products

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Rooftop Cargo Box on Car

If you’re looking for extra storage space and you don’t have a lot of room in your vehicle, a roof cargo box may be the perfect solution. But with so many different models and brands available, it can be difficult to know which one is right for you. In this guide, we will walk you through the process of choosing a roof cargo box and help you find the perfect one for your needs.

How to Choose a Roof Cargo Box

Having the perfect cargo box for your trip will not only take the stress of a packed-to-the-brim car off your shoulders, it will also allow you to bring everything you need for your epic adventure. However, if you want the best, you will need to carefully consider several important factors, including your plan for the roof cargo box, the size, fuel economy, ease of access, and several other factors.

In the end, everything boils down to your requirements, and you just need to pick the option that best fits your preferences. Keep reading for some tips of how to choose the right box as well as our favorite product recommendations.

How Does a Roof Cargo Box Work?

Cargo boxes are essentially containers that are secured to the roof of your car (usually by connecting them to crossbars). They will take some setup to be placed on top of any automobile, so you should plan for an hour or two to get everything secured. You might want to take a slow drive through your neighborhood before hitting highway speeds to make sure everything is secure.

Most cargo boxes also have locking mechanisms, so you can keep your belongings safe when you’re parked. Make sure you test the locks a few times before heading on your grand adventure. Sometimes they can be a little finicky (especially if your cargo box has gone on a few adventures already).

Steps on Choosing the Best Cargo Box

Step 1: What are you planning to store on it?

When searching for a cargo box, it is important to keep in mind the dimensions that your belongings demand, including the container’s height, width, and length. When you are doing this, make sure to keep the following things in mind: Objects that are both bulky and compact can be stored effectively in roof boxes. Things that are longer need a roof box that is also longer. It is best to keep things that are heavy inside of the vehicle. So, for example, if you’re wanting to transport your skis or snowboard, you’ll need to make sure the cargo box can fit them adequately.

Step 2: Analyze the dimension of the cargo box

When buying a cargo box, you not only want to pay attention to the size of the items you want to store in the box, but you also need to consider the size of your car. If the cargo box is too long for your car, you might have troubles with the hatch not being able to open. Or even worse, it could be longer than your car itself!

Step 3: Aerodynamics and fuel economy

We wrote a whole article about the impact on fuel economy by cargo boxes, so check that out for ALL the details: How much does a roof box affect gas mileage? We dug into the details!

But as a general rule of thumb, you should look at the aerodynamics of the box you’re purchasing. For example, if you’re going on a cross-country roadtrip, you’d probably want to go with a sleep, aerodynamic box, as opposed to a more bulky (and less aerodynamic) bag. But if you just need the extra space for a long weekend a couple hours away, a bag might be the more cost-effective and better option. We broke down the difference between cargo bags and boxes in this article: Vehicle Cargo Box vs Cargo Bag: What is the difference?

Tips for using a Roof Cargo Box

1. Consider the weight capacity of your roof cargo box

Looking to put light items in your cargo box? Or are you trying to transport bricks and stones? (Not sure why you would need to do that, but hey, we don’t judge…). Each cargo box will come with a weight capacity. Make sure you take a close look at that when buying a cargo box. Of course you also need to consider whether your car (and the crossbars you’re connecting to) can carry the weight you’re wanting to haul around.

2. Keep items you need handy in the vehicle

To refrain from making repeated trips to get items from the cargo container, only pack items you won’t need until you reach your destination. Items you frequently need, such as refreshments, beverages, children’s toys, and novels, should be stored in the car.

3. Know the height of your vehicle with the cargo box

To avoid accidents with low structures, it is crucial to know the height of your car, also with cargo boxes or any other items on top. Thus, whenever you see a notice saying the height, you will understand whether or not you can enter. Use a measuring tape and make notes of its measurement, so you don’t miss it.

Product Recommendations: Our favorite Cargo Boxes

SportRack Vista XL Rear Opening Cargo Box

The first cargo box is the SportRack Vista XL. This box is 62.5 inches long, making it a great option for storing longer items. It is also 39 inches wide and 19 inches high, making it a good choice for storing a variety of items. The SportRack Vista XL weighs 28 pounds and has an internal capacity of 18 cubic feet or 510 liters.

What’s cool about this cargo box is that is opens from the rear, meaning you can actually access it from three sides, as opposed to many other models that can primarily be accessed from one side. This is nice because sometimes your adventures take you to places where one side might be more difficult to access, but this box will leave you two other options even if one is blocked.

Thule Motion XT Rooftop Cargo Carrier

The second cargo box is the Thule Motion XT Rooftop Cargo Carrier. Available is L (16 cubic feet), XL (18 cubic feet) and XXL (22 cubic feet), this is a very nice, high-end option. With its sleek design, this box is sure to add a cool aesthetic to your car. The XL version weighs in at 55 pounds with dimensions of 91/5 x 37/5 x 18 inches, whereas the smaller size L weighs in at 42 pounds with dimensions of 77 x 36 x 17 inches. They also come in two colors: Black and Titan.

Thule is well known in the cargo box space as one of the main players. We found the product on Amazon (see here), making it easy to order ahead of your next adventure.

Yakima SkyBox 16 Carbonite

The third cargo box is the Yakima SkyBox 16 Carbonite. This box is 81 inches long by 36 inches wide and 15 inches high, making it a good option for fitting lots of gear. In their product description, Yakima boasts that this box can store gear for up to 3 people, including skis and snowboards up to 215 cm.

They also claim that their tapered design can reduce noise and getting in the way of the hatch. Nothing is more annoying than getting your cargo box mounted and you realize you can’t open the hatch anymore, so this is a great feature!

RoofPax Cargo Carrier Bag

The fifth cargo box is the RoofPax Cargo Carrier Bag. This bag is not technically a cargo box but can be used to store larger items on your roof rack system instead of in your car. The RoofPax Cargo Carrier Bag measures 47.2 x 35.4 x 19.8 inches for their 19 cubic feet model.

Available in several sizes ranging from 15 cubic feet to 23 cubic feet, this can be a great affordable option that will still allow you to store items on the roof of your car. According to the manufacturer, the bag is waterproof with double zippers, and can work with or without a roof rack.


There are a few main motivations behind our decision to purchase cargo boxes. Some of them are for business, while others are for vacations. However, if you install a rooftop cargo box on the vehicle, you will increase the amount of storage available to you. This will allow you to bring along all you need for such an enjoyable trip without having to bring your vehicle to its utmost capacity. We hope the information was helpful to you in selecting the appropriate cargo box.