How electric car range is increased: the invisible magic

Range with a full charge of the battery is one of the main indicators that electric car buyers and, of course, also their manufacturers pay attention to.

The latter have to solve the dilemma already in the design phase – how to get maximum performance while maintaining a competitive price. One of the ways to achieve the desired is to spell with aerodynamics.

The vicious circle

Although modern electrical systems and constant improvements in the charging infrastructure significantly reduce the charging time, it still takes much longer to fill the battery than it does to refuel. And if your destination is far from major roads, there's no saying you'll find fast charging stations. That's why electric car buyers still pay a lot of attention to mileage, or range with a full charge.

At first glance, it might seem that this is an easily solvable problem – you just need to put a bigger battery, and that's it! But… it creates a vicious circle. A large battery makes the car much more expensive and much heavier, which causes a number of other problems - reduced performance, reduced efficiency and, therefore, range. After all, it takes even longer to charge.

The capacity of batteries to be installed in electric cars is currently adjusted by people's everyday life. It shows that a 50 kWh battery is enough for city routes, which can actually drive 300 km. For mid-range models, they are 70-80 kWh, which can be used for 400-500 km. Finally, large and heavy cars, including from the luxury segment, need a battery of about 100 kWh, which gives a range of 400-500 km.

What does aerodynamics do?

Since it is not possible to squeeze much more range out of the battery alone, engineers have to look for other avenues of optimization, and one of them is aerodynamics.

The biggest stumbling block for electric cars is efficiency on the highway. Most electric cars don't have a gearbox because they don't need one: maximum torque and power are available throughout the rev range. However, when driving at high speed, the engine is constantly working at increased revolutions, and then more energy is wasted, and the air resistance does not increase linearly. Good aerodynamics reduce air resistance and allow you to deal more effectively with the invisible obstacle.

Toms Timoshko, car reviewer of Klubs magazine

Research in this direction continues for many decades, but the electric car is ready to roll up its sleeves and try harder. So everyone is diligently looking for the most efficient body shape.

The impact of aerodynamics on electric cars can be seen by comparing two Hyundai models, the Ioniq 5 and Ioniq 6. Both share the same platform, identical electric motors and 74 kWh batteries. But one is a stylish, tall and angular crossover, and the other is a long and low sedan. According to the WLTP protocol, the crossover Ioniq 5 version with rear drive and one electric motor can travel 507 km, and the sedan Ioniq 6 – 614 km. The difference exceeds 100 km, although the only significant difference is the shape of the body. The aerodynamic coefficient of the Ioniq 5 is 0,288 Cd, while the Ioniq 6 is only 0,21 Cd, which makes it one of the world's "smoothest" cars in terms of aerodynamics.

Crossovers can also be aerodynamic

One brand after another continues to create electric sedans and station wagons with a low, rounded body. Thanks to good aerodynamics, they are able to cover a considerable distance - Volkswagen ID.7, BMW i5, Mercedes EQS and EQE have appeared on the market, and Tesla models also have good aerodynamics. However, the majority of buyers do not particularly like these cars and still prefer SUVs and crossovers. Their high body creates a lot of air resistance, so manufacturers try to turn everything for good with smart solutions. 

Part of aerodynamics lies in the small details that are often not even visible, but if they are done right, even a narrow, angular vehicle can be quite effective. For example, modern bumpers direct the air flow so that it does not end up in the wheel arches. The surfaces are designed so that the air sliding along them separates without creating eddies. Therefore, a modern tank can turn out to be better than an aerodynamic masterpiece produced twenty years ago.

Toms Timoshko, car reviewer of Klubs magazine

It turns out that no matter how aerodynamic the top of the body is, harm to aerodynamics can come from below, where turbulence is created by various structural elements. Models developed on electric car platforms have advantages in this regard - their bottoms are mostly completely flat. But the problems are in the wheels - they create quite a lot of resistance, and since they are in contact with the road and drive over various obstacles, they cannot be covered either.

Hyundai has developed the E-GMP platform, which creates a flat bottom, and thus the company has created a solution to this problem as well. The Active Air Skirt technology includes two additional deflectors integrated into the front bumper. When the driving speed reaches 80 km/h, they descend in front of the front wheels, forcing the air flow to move around them and preventing the formation of strong turbulence. This system also works when the speedometer reads beyond the 200 km/h mark.

The little enemies of aerodynamics

In order to eliminate even the smallest pests of aerodynamics, companies come up with new solutions. One of them is digital mirrors. They are actually miniature cameras, with much less air trapped behind them than traditional exterior mirror ears. Depending on shape and speed, digital mirrors reduce drag by 2-7 percent. Audi was the first to use them on a large scale in its e-tron, but such mirrors are also found in cars such as Hyundai Ioniq 6 and Honda E.

Another solution – for example, Hyundai recently presented an innovation – active aero elements called air skirts. When driving at high speed, they reduce turbulence under the car and, accordingly, aerodynamic resistance.

Another trick used by many manufacturers is a closable air hatch in the front of the car. When extra cooling isn't needed, they close because every dimple and hole adds resistance, which in turn hurts efficiency.