Tent is a staple when it comes to camping. You can either choose from the traditional one or the roof top tent. Both have their advantages and disadvantages, and the type of tent all varies in different aspects like affordability, weight, design, portability, weather, among others. For a roof top tent, though, one of the main and important factors you need to assess before buying and installing one is the weight limit of the car roof.
- If you just recently discovered the beauty of having a roof top tent, this is how to determine the weight capacity of the car roof and know if it is roof top tent friendly.Look for your car’s permissible roof load which can be found in the operating manual of your car’s manufacturer.
- Distinguished your car’s dynamic rating.
- Crucial calculations:
- For the roof load: The total weight of the roof top tent, additional load on the roof, and roof rack should not exceed the permissible roof load.
- For the roof rack: The weight of the roof top tent on top of the additional load on the roof rack should not weigh more than the allowed maximum load of the roof rack.
- For the total weight: The total weight of the unoccupied vehicle, passengers, roof rack, luggage, and roof tent should not go beyond the total permissible vehicle weight.
- Determine the permissible total weight of the car, which can be found in the car’s registration document. This is the vehicle’s empty weight plus the maximum payload.
From the look of it, it doesn’t sound like it’s an easy and fun task compared to shopping brands and designs of an RTT. It is not. It is tedious yet important.
The Importance of Roof Load
One can’t just simply go shopping for a roof top tent without doing the math. By doing so, you are protecting your car’s performance and the people who ride in it. Even if the rule of the thumb is to limit the total carload to not to exceed the total mass of the car, if your roof top tent and roof rack alone has already weighed more than the permissible roof load, you are still putting everything and everyone at risk.
The roof load is limited to avoid loss of driving dynamics. When you load heavy equipment on top of your car, the change of gravity will make your car swerve more when you do a corner, or there’s a good chance of rolling over when driving on a slope or uneven exterior. The increased center of gravity brought about by overloading can affect the acceleration and brake capability, which are dangerous, especially on winding roads. In addition, when vehicular accidents occur, car insurances won’t be liable for any damages and cost if found out that there has been a roof overload.
Now that we have established the significance of roof load, we can now proceed with determining the weight capacity of the car roof.
How To Tell
Determine the Permissible Roof Load
Permissible roof load is the weight capacity of the car roof allowed by your manufacturer. This information can be found written in the operating manual. The weight capacity of the car roof or permissible roof load is different from each car model. Also, don’t confuse it with the permissible total weight of vehicles found in the registration document. Those two are different, which will later be discussed. The total weight of the roof top tent, the additional load on the roof such as ladder and camping equipment, and the roof rack itself should not exceed the weight capacity of the car roof. So, if your permissible roof load is 110lbs and your roof top tent weighs 70lbs, you will only have room for 40 more lbs for your roof rack and additional items.
Determine Car’s Dynamic Rating
There are two kinds of roof top weight limits that you must distinguish: the DWC or Dynamic Weight capacity and SWC or Static Weight Capacity. DWC is the weight your roof rack can physically hold while your car is in motion. With that being said, it is important that the DWC of your roof rack is at least the same as the weight of your RTT. If your RTT weighs 70lbs, your roof rack should also have a DWC of at least 70lbs. SWC, on the other hand, is your roof car’s ability to support not only the weight of the tent but also the occupants when not in motion. Generally, Static rating is much greater than Dynamic. Those two have different weight limits and are different in each vehicle, so it is important to check them with the manufacturer. Overloading in either aspect may affect any insurance claim.
Choosing The Right Roof Rack
Roof rack not only holds your RTT safely in place, but it also helps in spreading the weight evenly across the car frame. The weight of the roof top tent on top of the additional load on the roof rack should not weigh more than the allowed maximum load capacity of the roof rack. And before purchasing RTT, you need to make sure you have a good rack system that can hold them. You do not want to just erect your tent to any rack. There are different kinds of roof racks out there, and not all are compatible with RTT. Choose those that are specially designed to handle a gradual increase in weight.
Permissible Total Weight of Car
This is the vehicle’s empty weight plus the maximum payload, not limited to roof weight. It can be found in the car’s registration document. The total weight of the unoccupied vehicle, sleepers, roof rack, luggage or equipment, ladder, and roof tent should not go beyond the total permissible vehicle weight.
Do I need to detach my roof top tent during car wash?
For frequent campers, removing the roof top tent from time to time can be a lot of work. However, you will be risking a lot of things when you bring your car with RTT still on it. Your RTT will suffer from high pressure and stress from abrasion, which will contribute to a faster deterioration of your tent. It’s prone to possibly breaking any car wash machines or equipment, which is a liability you do not wish to have. Or worse, it will damage your vehicle or tent. Sure, you can bring your car in, but the permission of the car wash owner is still needed.
Same goes for the roof rack. The brush mechanic can snag the corner or edges of your rack, which can cause damage to your rack, your vehicle, or the car wash itself. If you wish not to detach your RTT or roof rack, you can hand wash it with mild detergents to avoid damage on the material. You will have the chance to inspect it or for any possible damage or need for replacements. Still, taking it off would be better for a full clean up, plus you’ll be able to clean the top of your roof, too.
Can I leave the roof rack on my car?
If there isn’t a need for cleaning or maintenance, it is ok to keep them on. Some racks, however, can affect your car’s performance, so owners remove them if not needed. Luckily, there are roof racks developed to be aerodynamics with less wind noise and less drags. So, if you wish to keep them on, look for rack design that doesn’t affect your car performance on the road or your MPG. Roof rack tends to impede the airflow from running smoothly over the car roof. That alone increases the Cd and affects your gas mileage by lowering it to 10 percent. Now, if you are looking forward to a long drive without needing to load anything on the roof, consider removing it to make the most of your road trip.
Is there an alternative if my car roof load is low?
Yes. This matter is not uncommon, so there are manufacturers who came up with an innovative idea of designing an inflatable roof tent. They are light and easy to stow that you can assemble them in just a few minutes.
Checking the weight capacity of the car roof requires work. However, soon as you get past that, it all will be smooth sailing after. If you are a noob in this, don’t hesitate to reach out to your outdoorsy friends or experienced campers for any tips. You’ll have peace of mind driving your tent and sleeping in it, knowing that you are safe from any disaster. After all, it is not the destination but the journey that matters.