Yes, the maximum roof load is often lower on older cars than on newer models. Over the years, manufacturers have improved roof structures and mounting points, meaning that more modern cars generally have a higher permissible roof load. However, there are exceptions, and the year of manufacture is only one of the factors determining the maximum roof load. In this article, we answer the most frequently asked questions about roof load, roof racks, and the safe use of a roof box.

Why does the maximum roof load differ by car and year of manufacture?

The maximum roof load varies by car and year of manufacture because manufacturers redesign the roof structure, body stiffness, and roof rack mounting points for each model and generation. Older cars are more often built with less optimized roof structures, resulting in a lower permissible load. Newer models benefit from lighter but stronger materials and better engineering standards.

In addition, the type of car plays a major role. A compact hatchback structurally has a different roof plane than an SUV or a station wagon. SUVs and station wagons are often designed to carry extra luggage, making their roof construction naturally more robust. Older compact models from the 1990s or early 2000s frequently have a maximum roof load of only 50 to 75 kilograms, whereas modern family cars and SUVs easily allow 75 to 100 kilograms or more.

The year of manufacture therefore says something about the technological generation of a car, but it is the specific model and the bodywork that ultimately tip the scales.

How do you find the maximum roof load of your specific car?

You can find your car's maximum roof load in the vehicle's owner's manual, on the type plate in the door, or on the manufacturer's website. This number is listed as “maximum roof load” or “maximale daklast” and is binding: it is the limit guaranteed by the manufacturer for safe use.

Don't have the manual at hand anymore? Then there are two reliable alternatives:

• The car manufacturer's website: Search by your model, year, and engine variant for the exact technical specifications.
• The configurator of Hapro: via the Hapro website you can quickly check which roof rack and roof box fit your specific car, including information about the roof load limit.

Please note: the value in the manual applies to the complete system on the roof, including roof racks, roof box, and contents. Therefore, do not calculate based solely on the weight of the box itself.

What factors are included in the maximum roof load?

Everything placed on the car roof counts towards the maximum roof load: the roof racks themselves, the roof box or roof rack, and the entire contents of the box. Therefore, you must add the weight of the empty roof racks and the empty box to the weight of your luggage before calculating the limit.

A practical calculation example: suppose the maximum roof load of your car is 75 kilograms. Your roof racks weigh 4 kilograms together, and your roof box weighs 15 kilograms. That leaves you with 56 kilograms for the contents of the box. Sounds like enough, but a family with skis, boots, jackets, and suitcases fills that up quickly.

Also, do not forget that the roof load affects handling. A heavily loaded roof raises the car's center of gravity, which impacts stability, especially in corners and in strong winds. Therefore, always keep the load as low as practically possible, even if technically you still have room below the maximum limit.

Is it safe to use a roof box on a car with a low roof load capacity?

Yes, a roof box can be safely used on a car with a low roof load, as long as the total weight of roof racks, box, and contents does not exceed the maximum roof load. It is a matter of planning: choose a lightweight box, use lightweight roof racks, and only take what is really necessary.

With a low roof load of, for example, 50 or 60 kilograms, the choice of the roof box itself is decisive. A heavy, large box leaves little room for contents. In that case, consciously choose a lighter and more compact model. Thanks to improved material usage, modern roof boxes have become increasingly lighter without compromising on sturdiness.

Safety also starts with the attachment. Ensure that the roof racks are approved for your car and that the roof box is locked correctly. Hapro roof boxes They are TÜV-certified and tested for crash resistance, vibrations, water, and wind, providing extra safety, even on cars with a limited roof load.

Which roof box is suitable for a car with a limited roof load?

For a car with a limited roof load, it is best to choose a roof box that is lightweight, compact in size, and dynamically shaped. A smaller box weighs less, leaves more room for contents within the roof load limit, and experiences less drag on the highway, which also reduces fuel consumption.

For a roof load of 50 to 75 kilograms, consider a roof box in the 300 to 400-liter range. The Hapro Roady with 300 liters is a good example of an entry-level model that is compact, lightweight, and practical. For those who need a little more space without adding too much weight, the Traxer is a versatile choice with its double-sided opening and availability in multiple sizes.

Unsure which model fits your car? Use the online configurator on the Hapro website or contact for personal advice. We are happy to help you find the right combination of roof rack and roof box that fits within the limits of your specific car, so you can hit the road worry-free.