How to Make Roof Racks More Aerodynamic, and Why It Is Important

We discuss three ways to make your roof rack more aerodynamic and explain why it matters a lot.
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Last updatedLast updated: July 06, 2022
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When we’re talking about vehicle aerodynamics and how to make roof racks more aerodynamic, note that it’s more than just vehicle speed and drivability.

Curse and blessing at the same time: aerodynamics also applies to roof rack installations. Poor aerodynamics is often manifested by loud wind noise, which sometimes grows into a shrill whistle. You may have been asking, “Why is the roof box whistling?” and “why is my vehicle consuming more fuel since I installed the roof rack or box?”

What the hell is that? The faster you drive, the worse the wind noise. Worse still: The noise degenerates into a veritable whistling concert that gets on your ears badly. Do you want to endure that over hundreds of kilometers?

You don’t have to endure this annoying whistling of the roof box and constant stops at fuel stations. If you know the causes, you get the solutions. In this article, we’ll see how to make roof racks more aerodynamic.

Why Roof Rack Aerodynamics Matter?How to Make Roof Racks More Aerodynamic, and Why It Is Important

Aerodynamics Trusted Source Car aerodynamics | How a Car Works As the cost of petrol rises, car manufacturers are taking more and more care in designing their cars to be fuel efficient. www.howacarworks.com  is an inevitable topic for travelers with roof racks. It has a lot of effect on your car, driving speed and ease, and even passenger comfort.

Do Roof Racks Affect Your Car’s Speed?

Adding or improperly installing a roof rack will affect the speed of the car because two streams of air are now colliding – the one from the car and the one from the roof box – air vortices are then created, which results in a drag that reduces speed.

You perceive these vortices as loud wind noise. Sometimes even as whistles of the roof box. This is usually due to the incorrect or sloppy installation of the rack or luggage box.

Is There Any Effect on Fuel Consumption?

A Berkeley Lab research has found that  1% of annual fuel consumption Trusted Source Roof Racks a Drag on Fuel Economy - Berkeley Lab newscenter.lbl.gov  is lost to roof rack installation in vehicles. Your car’s fuel consumption will likely increase with installing a roof rack, but this increase will depend on several factors. This can include the weight of the load, the shape or design of the roof box, and more.

Do Roof Racks Impact Your Vehicle’s Handling?

Yes, they do! When a roof rack is fitted, the height of the vehicle affects the gravity center of the car. This reduces on-track performance. Then the overall handling of the vehicle is affected.

How Do You Know the Aerodynamic Efficiency of Your Roof Rack Needs Improvement?

You should keep your eyes peeled for some signs to know how efficient your vehicle’s aerodynamics is after installing a roof rack.

Noise and Whistling

Rooftop racks can create noise in a vehicle, but the intensity depends on the rack, how it’s installed, and the type of vehicle. If the aerodynamics aren’t efficient, then the rack will generate a lot of noise.

Vibration

How to Make Roof Racks More Aerodynamic, and Why It Is ImportantThe aerodynamics of your racks need improvement when you can feel vibrations and hissing house from the rooftop. This is a sign that the wind is working against your vehicle. A wind deflector or fairing may help. One of the most recommended by vehicle owners with roof racks is the INNO INA261 Fairing. It’s a medium universal mount that deflects air up on midsized cars and SUVs, thereby preventing air from passing beneath the rack and improving aerodynamics. You can also use rack pads if the noise is a lot.

Rack Shape

How to Make Roof Racks More Aerodynamic, and Why It Is ImportantThere are four different bike racks, but the rooftop rack affects aerodynamics most because it’s standing in the way of airflow and will be dragging your vehicle back.

Not just that, you’ll be paying more for gas. Instead of a rooftop bike rack, why not install a hitch rack. A hitch rack is at the back of the vehicle and goes in line with the vehicle’s direction, hence, eliminating drag and unnecessary fuel consumption.

If you have to choose a room rack, choose models that can be folded down when not used. These can be found in many models in the best double kayak roof racks.

Resistance

The main reason a car’s gas mileage is affected by a roof rack is the wind resistance it creates.

Some roof racks are not as aerodynamic as they could be, and as a result, the strength of the car is affected, leading to increased fuel consumption. When the vehicle is not aerodynamic, you’d feel some resistance at the wheels and even in the car while driving. This is also caused by a high drag coefficient Trusted Source What is Coefficient of Drag—And Why Should You Care? Aerodynamics are everything. Improve yours. autos.yahoo.com caused by the extra loads.

3 Ways to Make Your Roof Rack More Aerodynamic

So, having discovered what the problem is, how can you remedy it? Here are some tips.

#1: Use an aerodynamic roof box

How to Make Roof Racks More Aerodynamic, and Why It Is ImportantBefore you think about how to transport bulky objects on the car roof or in a roof box, you should first get a roof box. A roof box may provide limited space, but it’s designed with a lower front that acts as a wind deflector. This ensures more aerodynamics – and it will even make your vehicle look more aesthetic.

Among the best Thule roof racks, you’ll find closed roof boxes that will ensure more aerodynamics. The allegedly quietest and most aerodynamically efficient Trusted Source Yakima Products Garners Two Industry Awards at 2011 Outdoor Retailer Summer Market - Largest U.S. Outdoor Trade Show www.prnewswire.com roof rack is said to be the “Whispbar” from Yakima. This fuel-efficient carrier model was developed and optimized with technicians from the University of Canterbury, and the designer is a former aircraft engineer. Reducing wind noise, resistance, and vibrations is the top priority with this simple carrier.

#2: Reinstall Your Rack/Box

How to Make Roof Racks More Aerodynamic, and Why It Is ImportantThe primary requirement for attaching a roof rack or box is the structure. There are different ways to attach a roof rack. Depending on whether the car roof has an open or closed roof rail, a rain gutter, a fixed point attachment, or a T-slot profile, the choice of the right roof rack is determined.

Furthermore, roof racks differ in their shape, strength, and material. These factors affect aerodynamics, fuel consumption, and noise levels while driving.

It is advisable to ensure that the roof rack does not protrude at the rear or the front. The further the roof box or rack projects, the poorer the aerodynamics, the higher the vehicle’s drag coefficient (cd value), and the higher the fuel consumption.

Also, while reinstalling or at the point of installation, you can use aerodynamic crossbars such as the JetStream Bar from Yakima. The aerodynamic crossbars are designed for roof rack systems and minimize drags.

You can also make a deflector yourself. The video below shows you how!

#3: Load the Roof Rack Correctly

You only pack as much on the roof rack as the permissible roof load allows. Moreover, the maximum weight of the roof box must not be exceeded. If possible, heavy objects should be placed in the trunk.How to Make Roof Racks More Aerodynamic, and Why It Is Important

The roof rack should be loaded correctly to counteract the damaging effects of shifting the center of gravity.

You can use this checklist as a guide when loading:
  • Distribute the load evenly
  • Place heavy objects close to the ground and in the middle
  • Fill cavities efficiently with bags or sleeping bags
  • Tie the luggage with straps or a luggage net
  • Ensure you lock the car roof box

Should You Remove a Roof Rack When Not in Use?

Although Yakima, a rack manufacturing company, doesn't believe there are enough reasons Trusted Source Should You Take Your Car Roof Racks Off Occasionally - Yakima Once you have decided on a roof rack for your car and get it installed, you can use it to help transport your gear from one adventure to the next. Read more. www.yakima.com.au to take your racks off, we think you should. If, for example, you only use the roof rack or roof box for summer travels, you should remove them when you’re back from your summer travels. Unloaded roof racks tend to be noisier, and think about the fuel consumption over the months. It’s estimated that you’ll lose around 2 to 35% of fuel if you have your roof rack installed, whether loaded or unloaded.

If you don’t want to remove the racks during the time of use, then you should fold them down when not used. You’ll find, for example, among the best kayak roof racks on the market models that can be folded down for better aerodynamics.

Final Thoughts

Now you know how to make roof racks more aerodynamic. Of course, poor aerodynamics can cause high fuel consumption and wind resistance, affecting vehicle handling, noise, and safety.

Much more often, however, the cause is the rack, unfitting rack assembly, or the load. So there is room for improvement here. Take your time with the assembly and test the position of the roof rack so that you can achieve the best result.

Incidentally, the whistling is always an indication that the roof box is unfavorable to fuel consumption. Of course, it has to contend with higher air resistance. Finally, a roof box remains a flexible transport solution that offers you additional space.

References

1.
Car aerodynamics | How a Car Works
As the cost of petrol rises, car manufacturers are taking more and more care in designing their cars to be fuel efficient.
2.
Roof Racks a Drag on Fuel Economy - Berkeley Lab
3.
What is Coefficient of Drag—And Why Should You Care?
Aerodynamics are everything. Improve yours.
4.
Yakima Products Garners Two Industry Awards at 2011 Outdoor Retailer Summer Market - Largest U.S. Outdoor Trade Show
5.
Should You Take Your Car Roof Racks Off Occasionally - Yakima
Once you have decided on a roof rack for your car and get it installed, you can use it to help transport your gear from one adventure to the next. Read more.
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