Everything You Need to Know About Cargo Carriers for Cars

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Even if you buy the most spacious car or SUV in the market, you are still likely to run out of cargo space on special trips. There's always that one last thing or gear that won't fit when going camping, for a road trip, or any other adventure that demands a lot of cargo space. In those unique cases, folding rear seats isn't enough. It may not be an option if you have passengers. At this point, cargo carriers for cars are your best option.

What are Cargo Carriers for Cars?

As the name suggests, they are simply additional cargo carriers that add some much-needed space for carrying just about any cargo you can think of. 

Types of Car Cargo Carriers

Cargo carriers for cars are available in many types. Most categories focus on where they are supposed to be fixed in a car, i.e., rooftop cargo carriers and cargo carrier trailers.

The carriers are also categorized based on their features, for instance, there are lightweight cargo carriers for cars whose main feature is their lightweight capability and portability. There are also cargo carrier roof bags and cargo roof racks. Some carriers are also categorized based on their cargo capacity, waterproof or weather-proof capabilities, and securing mechanism.

Some cargo carriers will fit on the rooftop of your car whether you have roof rails or not. Others will sit inside roof baskets requiring a rack system and crossbars. Some carriers have padded mats for added benefits like preventing scratches and slipping.

Types of Car Cargo Carriers

In a nutshell, the market is full of endless cargo carrier options for cars. The carrier you choose for your car should be based on your unique cargo carrying needs.

To help you end up with the best car cargo carrier, car roof box, or whatever other names you call them, we've compiled and answered FAQs about cargo carriers for cars and covered many other important related topics for you. Here's what you must know before deciding on which cargo carrier, rooftop box, cargo trailer, or rooftop rack to buy for your car.

Are Cargo Carriers Legal?

Besides considering type, you should consider the legality of having a cargo carrier on your car. Most states have different laws on towing and using cargo carriers. To be absolutely sure you aren't breaking the law, check your local DMV (Department of Motor Vehicles).

Local DMVs have all the motor vehicle information you need on user licensing to trip permits and special equipment. While cargo carriers aren't illegal in America, general rules must be followed in all, if not most states. For instance, cargo carriers shouldn't be installed in an area that obscures your car's tail light or license plate.

If your cargo carrier must be installed in an area that blocks the license plate or tail lights, does the law in your state allow you to relocate your license plates? Does the law apply only when the cargo carrier is empty? i.e., is it illegal to partially or completely obscure the license plate only if the cargo carrier is empty? These are some of the questions you should ask yourself, and your local DMV usually has the answers.

Everything You Need to Know About Cargo Carriers for Cars

Other legality questions include how far a cargo carrier should stick out. This question applies mostly to cargo roof carriers for cars that are either longer or wider than your car's dimensions or those that need to be attached like trailers.

Generally, the (DOT) Department of Transportation sets the general guidelines on regulations relating to overhanging cargo. For instance, states aren't supposed to impose overhang limitations less than 3-feet for front overhang cargo and 4-feet for rear overhang cargo applicable to trucks. As a result, you can have a cargo carrier in any state, provided it is within the applicable DOT guidelines. If you need more overhang space, you will need to check what your state says.

How Much Weight Can a Cargo Carrier Hold?

Another important question to answer before choosing cargo carriers for cars is the capacity/weight question! There is no definite answer to this given the amount of variables that come into play. For instance, the vehicle you have will dictate the cargo weight you can carry.

The laws of your state also dictate cargo carrier capacity. Considering debris flying off vehicles is responsible for multiple crashes as per the NHTSA, and a major cause of such crashes is poorly secured load, the importance of understanding factors like cargo carrier capacity can't be overlooked.

With that said, every car has its dynamics. For instance, are you driving an SUV that can hold more cargo or a small two-seater coupe that hardly has space? Every car, especially those that have cargo carrying capacity, have specific weight limits (dynamic and static weight limits). You can check your car's manufacturer's website for this information.

How Much Weight Can a Cargo Carrier Hold?

Dynamic weight capacity will let you know how much weight your car's roof can hold. Don't assume anything! Most SUVs are supposed to carry less weight on their roof than you would think i.e., approximately 165 pounds (74kg).

Smaller cars usually carry less than this. Crossover SUVs can carry 100 pounds (45kg). Since these are just general estimates, check your vehicle's driver manual for accurate weight restrictions and use this information to know the exact amount of weight your cargo carrier should hold.

What's more, weight isn't the only consideration to make. Related considerations like the cargo shape should be considered. Cargo carriers for cars meant to carry kayaks are aerodynamic. Generally, cargo carriers can carry more aerodynamic cargo than other cargo, which will create wind resistance and make the car feel unstable. So, as much as you may be within the weight limits, the shape of your cargo matters.

You should also focus on your car's static rating. Your car can hold more weight on the roof when stationary. If you wish to get a cargo carrier that can be used as a base for a rooftop tent, the static rating is important.

Are Trailer Hitch Cargo Carriers Safe?

Assuming you don't want a carrier for your rooftop, you have the option of choosing trailer hitch cargo carriers. How safe are these carriers?

Well, it depends on many things. Most hitch cargo carriers are either attached using racks or hitch frames. To be honest, provided you a buying the best brand of hitch cargo carriers, you can expect to get a high-quality attachment that will be safe for the intended use.

However, you must attach your cargo carrier as required. The best hitch cargo carrier won't mean much if it isn't attached properly. The material that makes the carrier will also dictate safety. Heavy-duty steel cargo carriers for cars with corrosion-resistant coating will withstand weather damage for decades without losing their structural strength.

Are Trailer Hitch Cargo Carriers Safe?

The carrier also needs to be made specifically for a car like yours. This information is provided with each carrier. Again, the best hitch cargo carrier brand may be unsafe when attached to the wrong vehicle.

Generally, the safety of a hitch cargo carrier starts with your needs and the vehicle you have. The tongue weight capacity will tell you the maximum weight a hitch cargo carrier should carry safely. Other considerations to make that dictate hitch cargo carrier safety include your car's rear design and wiring requirements if any.

Unless you are buying a carrier that will work safely with any vehicle configuration, you need to think about rear vehicle design elements like doors, tailgates, etc., as well as wiring that may allow your carrier to work with braking and signaling lights.

All in all, if you buy a notable brand specifically made for your car and follow all installation and cargo instructions, you shouldn't worry about safety.

Do Cargo Carriers Affect Gas Mileage

Most people also want to know how a cargo carrier will affect their gas mileage. Well, it depends on factors like the type as well as how heavy your cargo is.

While anything that increases the frontal area or load of a vehicle will affect things like aerodynamics and weight, which in turn directly affect gas mileage, there are specially designed cargo carriers for cars that won't increase fuel consumption as much.

Also, trailer hitch cargo carriers usually installed at the back may have less drag than those at the rooftop, meaning they'll offer better gas mileage. The location of your carrier will therefore affect mileage. You should expect your gas mileage to be poor when you install a roof rack and much poorer when you install a rooftop carrier.

The extent will be determined by factors like how heavy the cargo is and the aerodynamic features of your cargo carrier. For this reason, invest in aerodynamic roof boxes that don't affect gas mileage significantly.

Alternatively, you can consider trailer hitch cargo carriers that are at the back. What's more, you can purpose to remove your carrier when you aren't using it since driving around with a carrier (even if it is empty) has been proven to affect gas mileage.

Do Cargo Carriers Affect Gas Mileage

Weight has also been proven to increase fuel consumption. Heavier cars need more power to move. As a result, sticking to the most necessary cargo will help if you must use a cargo carrier and care about consumption.

Since cargo carriers (especially those mounted on the roof) will still lower fuel economy even when empty, it helps to have a roof-rack design that has an aerodynamic design. Instead of removing and reinstalling a carrier depending on usage, some cargo carriers come with crossbar designs that allow the racks to be put lengthwise when not in use to reduce drag. A longer roof box or cargo carrier will also be better than subcompact designs.

For a more accurate analysis of the effects of your cargo carrier on fuel economy, check your mileage logs first via the EPA's website to understand how your gas mileage will change.

Do You Need Crossbars for the Cargo Box?

If you decide to choose a cargo box as your preferred cargo carrier, you stand to enjoy notable benefits like secure and weather-proof storage for a variety of gear. However, your cargo box needs to be secured in place.

All cargo boxes need roof racks with crossbars. The best cargo boxes have universal mounting features that make it possible to attach to a variety of crossbars (whether square, round, aerodynamic, factory, etc.).

It's worth noting that you can secure gear on your roof using two main kinds of mounting, namely roof rails and crossbars. Cargo is secure on both. Roof rails are usually installed when a car is being manufactured. They run from front to back. Roof rails can be flash. Others are raised.

Do You Need Crossbars for the Cargo Box?

Crossbars attach to roof rails horizontally. They act as mounting points for cargo carriers. You need crossbars to secure a cargo box in place. There are many notable cargo carrier manufacturer brands like Yakima that sell crossbars for roofs without any railing. Such crossbars fit on the edge of a car's roof above the door.

What is better? A Cargo Box or Roof Rack?

A common question among car owners looking for cargo carriers for cars is whether they should consider a roof rack or cargo box. As mentioned earlier, there are countless types of carriers all with their pros and cons.

Roof racks have notable benefits like spreading weight evenly across a car's frame. Cargo boxes are placed directly on the roof, meaning all weight will be supported by the roof. In such a case, a cargo box may be better when you don't want additional space to carry very heavy cargo.

The most important consideration is your total rating to know exactly how much weight you should carry when your vehicle is moving. If your car's roof can handle 150 pounds and your rack is 30 pounds, you can only carry 120 pounds of cargo. If you have crossbars, you'll need to subtract their weight as well.

All in all, you may not be able to carry as much weight as you would think with a roof rack. The importance of considering every single factor can't, therefore, be overlooked. For a more in-depth comparison of Cargo boxes vs. Roof Racks, check out this article.

Should You Consider a Cargo Box, a Cargo Bag, or a Cargo Basket?

As mentioned, there are very many kinds of cargo carriers for sale today. If you are torn between cargo boxes, bags, or baskets, here's what you need to know.

All types of cargo carriers have their pros and cons. In regards to cargo boxes vs. bags, both offer additional space. However, cargo bags have a softer fabric resulting in less security. Cargo will also wiggle, creating problems like poor aerodynamics.

In regards to cost, cargo bags are definitely cheaper to buy. However, you have cons like safety that could have a cost implication. Cargo boxes are expensive to buy but cheaper to carry around if they have good aerodynamic properties. The same can't be said about cargo bags.

The battle between cargo boxes and bags is ultimately on security. Boxes are safe. However, you can consider a cargo bag when security isn't a huge concern since whatever you are carrying isn't that valuable.

For an in-depth comparison, check out our detailed cargo boxes vs. cargo bags article.

What about roof baskets? Well, by definition, a roof basket is a roof carrier mounted on a car. It can be designed using metal, plastic or other materials. The strongest materials are better for obvious reasons. Roof baskets are notable cargo carriers when you don't need to enclose cargo. They also don't usually need heavy-duty installation featuring drilling and other tedious tasks if your car has crossbars.

Roof baskets come in different models, varying depending on factors like the car. They can be used for many carrying applications. Since cargo isn't inside a box or bag, cords are used to secure your cargo for added security. They tend to have worse fuel economy than boxes and bags for obvious reasons. However, they are a notable option for individuals looking for cargo carriers for cars.

You can read our detailed top carrier boxes vs. carrier baskets to make a more informed decision.


The above information covers common questions asked by people before they decide what cargo carriers to buy. From the above, you can differentiate the different types of cargo carries for cars, if they are legal or not, how much weight you should carry on a cargo carrier, whether cargo carriers are safe and other important information i.e., the pros and benefits of different types of cargo carriers.

While there is still more to cargo carriers than what is covered above, you'll obviously find some value above when making your purchasing decision.

If you want to buy the most popular cargo carriers most consumers are buying, check out the best cargo carriers for cars in 2021. These cargo carriers meet unique needs and preferences of most people who have purchased cargo carriers for their cars.

About the author 

Vieira Babeker

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

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

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