A person opens their rooftop storage box

How To Find the Right Rooftop Box

Photo:alexeg84

To keep from overstuffing, rooftop boxes and racks can make all the difference.

When you load up your car with overnight camp equipment, the available room for storage disappears fast. To keep from overstuffing, rooftop boxes and racks can make all the difference. They not only add more room to haul your gear, they also free up interior car space. That means a more comfortable commute to the trailhead while protecting your goods against rain, sun, and wind. Knowing which rooftop storage system will best suit your needs depends on how much space you want to add and what type of gear you’ll be hauling. Because these rooftop systems can be expensive, it’s important to choose wisely. Here’s a breakdown of different storage boxes and racks, how to install them, and how to make the most of the added space. 

Types of Rooftop Boxes

Hard-shell Boxes

Rooftop hard-shell boxes come in many shapes and sizes, and can accommodate everything from a family’s set of seven skis to a month’s worth of summertime camping gear. Made from tough, composite plastics designed to reliably fend off weather for years, hard-shell boxes can weigh up to 60 pounds and cost upwards of $800, but they can hold more than 500 liters in some cases. Most hard-shell boxes add security with locks built into their latches. 

Pros: Maximum storage space; highly durable; security features.

Cons: Heavy, can be pricey; can require additional mounting equipment (crossbars); hard to store; some might be too long for compact cars.

What to look for: Dual-sided opening capacity—it’s much easier to organize and retrieve gear when you can see and access it from both sides of the box. Internal straps that’ll help secure items and keep them from sliding around during your drive. Also consider aerodynamics, which matters more for cross-country long hauls. A box’s shape can also influence how noisy it is and how much it reduces our gas mileage (more details below).

Soft-shell Boxes

Instead of rigid plastics, soft-shell boxes are made of pliable-yet-durable materials. With a range of 250 to 450 liters, they offer as much storage as hard-shell boxes, but can be easier to install, remove, and fold up for storage when not in use thanks to their lighter weight (6 to 8 pounds versus a hard shell’s 20-plus pounds). Typically more economical than hard shells, soft-shell boxes are great for folks on a budget or those interested in trying rooftop storage for the first time. 

Pros: Respectable storage space; easy to store; easier to install; don’t require crossbars.

Cons: Can be less aerodynamic; risk of puncturing material when packing sharp objects.

What to look for: Ultra-durable, water- and windproof materials like vinyl or PVC; dual-seam construction and covered zippers to truly keep out the elements; and compression straps, which will help secure the load. 

Racks and Baskets

Are you hauling various oddly shaped items like, say, a cooler and a kayak and three camp chairs? A roof rack or basket are great for awkward, self-contained, and large items that may not fit into a hard- or soft-shell box. A rack sits flat on top of your vehicle, providing ample tie-in and strap-down points for all sorts of awkward items; a basket has a rim around the rack that adds more tie-in points and helps keep items secure within the basket.

Pros: Great for large and awkward objects; economical option; easy to install and no need to remove when not in use.

Cons: No protection against the weather; potential for flyaway items; need crossbars or base system.

What to look for: Sufficient storage space; weight limits.

An image of a rooftop box Photo:giadophoto

Installing and Mounting Rooftop Boxes

Do: Consider the stock rack system, if any, already on your vehicle. Some vehicles have raised side-rails, flushed side-rails, or fixed tracks (all three run the length of the car); others come with factory crossbars preinstalled. Some vehicles have mount points hidden by small protective coverings on the roof; these can be used to install a variety of roof racks. For most hard-shell boxes, you’ll need crossbars, but for soft-shell boxes and racks, fewer pre-installed materials are needed.

Hard-shell box: Your box might come with mounting crossbars, or you might have to buy them separately. The right mounting system will depend on the rooftop box brand and what infrastructure is available on your car’s roof. Note: Some boxes are only compatible with their company’s racks, and some crossbars are rounded while others are flat, so check what type of crossbar your hard-shell box requires. Crossbar installation typically takes around 30 minutes. Once installed, mounting the box involves setting it on top of the crossbars, then securing the box to the crossbars—either by clicking together an interlocking mount system or wrapping secure clasps around the bars. Overall, installing your box in a central position is best, but if you have to choose one side, mount it on the passenger side; that placement positions you away from traffic when loading and unloading.

Soft-shell box: You can install soft-shell boxes without any type of outdoor equipment on the roof of your car, or you can use any existing infrastructure like side-rails (running the length of the car), crossbars (running the width of the car), or a rack or basket. First, clean the roof of your car and install an optional protective mat (to protect the car against scratches). Place the soft-shell box on your roof, orienting it correctly (front and back should be noted) and leave at least 8 inches of space between the front edge of your car’s roof (where the windshield ends) and the front edge of your soft-shell box. Use the adjustable straps to fasten the box, either by looping them through the car windows (in the case of a blank car roof), or by using available infrastructure like rails, crossbars, or a rack’s bars.

Rack or basket: Racks and baskets will work with most types of crossbars, but look for specific compatibility with flat or rounded crossbars.

Using Rooftop Boxes

Do: Pack smart. Most rooftop boxes will come with a load capacity. Be careful not to exceed the weight indicated, as the mounting systems aren’t reliable with overweight loads.

Hard-shell boxes: Put the heaviest items in the middle of your rooftop box to help equalize the car’s weight distribution and improve your fuel economy. If available, use internal straps or holders to fasten your gear to the bottom of the box, reducing movement inside the box. This will cut down on noise, further improve fuel economy, and keep your gear safe from scrapes and scratches against other items.

Soft-shell boxes: If available, use compression straps to tighten the soft-shell fabric down and reduce any movement inside the storage space. If you’re looking to add the lock-and-key security of a hard-shell box, add small luggage padlocks to the zippers. Take care when packing items with sharp sides: Don’t stress the seams and zippers by overstuffing, which can weaken and cause them to fail.

Roof rack and baskets: Fix a cargo net across the top of a roof rack or basket to help hold down smaller items or potential flyaways. It provides a second line of defense against items already strapped down. 

Do: Pack aerodynamically. Consider weight distribution and location. Look for lower-profile boxes. The higher the box, the more wind resistance it adds to your vehicle. The most aerodynamic boxes are 17 to 20 inches high, have a tapered design, and a hard shell. 

If you’re concerned about gas mileage and aerodynamics, don’t attach your rooftop box unless you’re actively using it. According to Consumer Reports, even an empty rooftop box can significantly impact a vehicle’s fuel economy: It found an empty roof rack had nearly a 2% impact on fuel economy, while adding a box resulted in a 13 percent loss in fuel economy, or just over 5 mpg, per hour.

Don’t: Strain your back. When loading your rooftop box, enlist a friend! Lift heavy items up together to place them in your box. If you’re rolling solo, lift with your knees and gently press the items over your head. 

Don’t: Hit your garage ceiling. A box will add height to your car—don’t forget to factor this into your driving and parking choices. You don’t want to smash into a garage ceiling or break your box against tree branches or tunnel ceilings, either. Measure the new height and heed any marked warnings.

All articles are for general informational purposes.  Each individual’s needs, preferences, goals and abilities may vary.  Be sure to obtain all appropriate training, expert supervision and/or medical advice before engaging in strenuous or potentially hazardous activity.

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