How does design impacts cars’ efficiency?

May 2021.- Good design not only helps a vehicle to be attractive, but it also helps it to flow through the air most efficiently. All the curves are designed to help the car use the least amount of fuel when it faces the wind. Since the last century, engineers have managed to improve the silhouette of cars influencing the body we see today.


A simple example to understand air resistance says Christian Scheel, Product & Sales Manager of SAIC Motor, manufacturer and owner of MG Motor, “when you are driving in a car and put your arm out of the window. On the one hand, if you put your hand perpendicular to the ground, you will feel the wind blowing, causing it to move backward; on the other hand, if you put it parallel to the ground, it moves with greater ease.”


Wind test


The closer a car is to a bullet or an almond-shaped silhouette, the easier it will be to pass through the air producing less drag and consequently expending less energy. “Besides the overall vehicle shape, there are also exterior elements that influence whether it is more or less aerodynamic, such as the design of the tires, the bumper, the side mirrors, and even the bars on the roof and the antenna,” added Scheel.


So, how do the manufacturers know if a vehicle is moving efficiently? The answer lies in the wind tunnel. This is where the conditions that a prototype would encounter outdoors at high speeds, are simulated through different sensors which measure the forces it produces at the front and rear of the car. A component is also applied to this wind flow and can be applied from the side to see, for example, how side winds impact the body.


“As well as aerodynamics, other aspects are also measured at this stage, such as the model stability, which also ends up influencing the final prototype design,” says the Product Manager. Other benefits added to the design are lower ambient noise and better engine and brake ventilation.


Perhaps the best example of a vehicle designed to defy the laws of physics is a Formula 1 car, but as aerodynamic as it is, this design is an impractical one to apply to all mobility needs.



“The shapes depend on the use or style of the car, so we see the models like the MG 6, with its fastback finish, or the recent MG Cyberster, which has a sportier profile, follow these thinner silhouettes in the nose and tail of the car,” explains Scheel, “if we look at the SUV, rather than ride fast, its purpose is to be practical, to move pets, put bags, or whatever you want, and therefore its shape tends towards a cube to have volume. However, the concept is still that they should be as aerodynamic as possible, to be energy efficient and safe”, concludes Scheel.