Efficiency is a term that has been thrown around often in the motoring industry over the last few years. As much as sports sedans are becoming more powerful, stringent emissions laws have forced manufacturers to get innovative when it comes to producing more earth-friendly machines. Feeding into this need for extra efficiency is the art of vehicle aerodynamics, and at our BMW body shop, we can modify your car in many ways which can improve the way it moves through the air.
Perhaps the ultimate display of aerodynamic efficiency has been seen in BMW’s i8 hybrid supercar. While Toyota’s Prius and Nissan’s Leaf have played important roles in showing how efficient an everyday family sedan can be, the i8 shows us how this philosophy can play out in performance cars too. Where aerodynamics are concerned, manufacturers often quote the drag coefficient (or Cd value) of a new car – this is defined as a dimensionless quantity which is used to measure drag or resistance of an object in a fluid environment such as air.
From a purely visual perspective, we can easily see why the low, sleek BMW i8 has a low Cd value of 0.26, while the bulky Mercedes-Benz G-Class SUV has a much higher Cd value of 0.54. A lower value generally equates to less drag, which means improved fuel efficiency and performance.
The following factors can influence a car’s drag coefficient:
Because this is the first point at which air travels around the bodywork, it makes sense that the design of the car’s frontal section heavily influences its Cd.
The i8 has a smooth, sealed underbody, an area of a car which although unseen, has a large effect on drag.
For the best drag efficiency, air should flow around rather than through the vehicle. The i8’s efficiency is aided by an almost completely blanked off kidney grille section, unlike in cheaper BMWs where air flows through the grille.
What does this mean for your car if you don’t own a specialized supercar such as the i8? Even a seemingly minor part such as mud flaps can affect a car’s drag, so there is much room for improvement in the aerodynamics of your vehicle. Our authorized BMW parts suppliers ensure that we can find the best parts for your car.
These are some of the ways in which you can improve aerodynamic efficiency through modified bodywork:
Many car owners (and especially owners of SUVs and wagons) have roof racks fitted which are almost never used. This addition comes with a hefty drag penalty, especially at highway speeds, since the part increases frontal area. By removing it, your car often looks sleeker, too.
Take a look at many BMW M performance models, and you’ll notice specially contoured side mirrors. While removing your side mirrors will be best for lowering drag, this obviously isn’t practical or legal. A compromise are sporty, slimmer side mirrors which reduce frontal area.
Your options here are vast. A modified front bumper section can instantly give your car a visual upgrade while being smoother and more aerodynamic than the standard version.
On older vehicles especially, the underside of your car’s body is often a mess of piping and metal, all adding to the Cd value. A smooth undertray made from aluminum or corrugated plastic can help to overcome this.
While vehicle aerodynamics aren’t always thought of as the first option for modification – often playing second fiddle to more power, flashier design, and mega exhaust systems – by taking some time to include aerodynamic upgrades to your car, you can drive off in a much more effective model that makes the best use of its power.
Visit our BMW body shop in Pompano Beach and find out how our bodywork specialists can help you find the best balance between style, power, and efficiency.
