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The Basics of Automotive Design
3 min read
By Benjamin Parker

The Three Pillars of Automotive Design

All cars that have a roof have three pillars, A,B, and C labeled from front to back, these pillars help to define the overall form of the car.

The A, B, and C, pillars of a car are the vertical supports of the upper window area of the car. Their design, and positioning are a defining characteristic of the car's form, and a signifier of their function. At a glance, what things stand out to you when looking at a car? For me probably the silhouette, the color, the brand, and probably the wheels. The body, and silhouette of the car is typically the first thing you notice when looking at a car. While body lines define the lower half of the car's silhouette, the three pillars in the upper portion of the car define the top half of the car.

The three pillars start with pillar A in the front, where the windshield meets the side of the car. The second being where the rear edge of the car door meets the body of the car. Finally the C pillar is the rear of the car where the rear windshield meets the end of the car and trunk. These pillars can be a definitive mark of a car. Let’s look at a few different instances of car brands.

A few tracings of the pillar layout of Porsche 911's over the years. When observed side-by-side you can begin to see how pillars help to define the visual language of a particular car model or brand.

Porsche has been making cars for a long time, and with some very small deviations they’ve stuck pretty hard with the same silhouette and general look for years. This is especially evident in the pillars. You'll notice that for the most part the B and C pillars have remained the same for years. It seems that only the A pillar gets longer and has a more shallow angle for better aerodynamics.

Apart from a few years of departure from it's standard form the pillar layout on the Ford Mustang has remained largely the same.

Another example of these pillars being a defining piece of a car is the Ford Mustang. The elongated slope of the A pillar and the large distance between the A and B pillars has remained the same. Also the tapered rear end the C pillar shaping a small rear window.

Although Tesla has only a few cars, when laid out next to each other you can begin to see the visual language that Tesla uses to design and layout all of their models.

The last example is Tesla’s lineup of cars. Although they haven’t been around for long their style has been definitive and different. Looking across three of the four cars in their lineup you can see that they essentially all share the same pillar set up even the larger Model X.

You can look just at these three arches and see the whole Porsche, or the whole Tesla. These illustrations are just derivatives of the actual design of these pillars but this exercise reveals that pillar slope, curve, angle, and placement are all elements that car designers can use to help define a model of car or the whole car brand itself.

The design of these three pillars isn’t merely for aesthetics, they each have a functional use that is relevant for the specific car. If you look at the pillars on a Land Rover Defender or any large offroading vehicle the pillars will be nearly vertical and probably more evenly spaced apart this is to allow for large windows to maximize viewing area, as well as rigidity to the body of the car. Sports cars like the Teslas and the Porsches have sleeker more angled lines that allow for less drag; better aerodynamics.


Car pillars are a few of the key elements that define the look of the car and communicate the function of the vehicle. The larger the ratio is from the A pillar to the B pillar the more aggressive the car will be. The smaller the ratio the more utilitarian the car will look.

Ben Parker
Ben is the founder of and lead writer at Voltage. A multidisciplinary designer with a passion for automobiles
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