Less resistance for more range and quiet: With its Cd figure from as low as 0.20, the EQS sets a new aerodynamic benchmark for production vehicles. This benefits the range. It is also among the best in terms of quiet running. A great deal of attention to detail lies behind the very good aerodynamic and aeroacoustic performance.
The purpose design with smooth underbody and mostly closed radiator shutter as well as the favourable basic shape were a good starting point for the flow optimisation. With a great deal of meticulousness, the aerodynamicists were able to achieve the new record Cd figure of 0.20 in close cooperation with the designers. The frontal area of the EQS is 2.51 m2. This results in an effective air resistance from 0.5 m².
The spread of the individual variants in terms of Cd figure is comparatively small - customers thus have a wide choice of models without having to consider the range. Mercedes also offers an aero wheel optimised in the wind tunnel in sizes 19, 20 and 21 inches.
Behind the very good aerodynamic performance is a lot of detail work. The EQS is the first representative of the new electric platform. This is why the invisible details, such as those on the underbody, were developed particularly intensively. Several thousand computational runs were performed in the virtual wind tunnel alone. Below are some details of the aero development:
- Aerodynamically favourable dimensional concept and tyres with optimised geometry
- Aerodynamically optimised wheels in the dimensions 19, 20 and 21 inches
- Cooling air control system with innovative transverse louvre makes extremely efficient use of the available installation space
- Continuous seals in the front area, e.g. between service flap, Black Panel and headlamps
- Streamlined design of the A-pillar
- Wheel spoilers at front and rear. The rear, arrow-shaped wheel spoiler was developed by a fluid dynamics expert directly in the wind tunnel for the benefit of a greater range.
- Elaborately matched underbody panelling in the rear-axle area to take even greater advantage of the smooth underbody of the battery.
- The rear spoiler benefits both rear-axle lift and aerodynamic drag.
For more than three decades, the aerodynamicists at Mercedes-Benz have been achieving top results. Currently, the A-Class Saloon (V 177) and the S-Class (V 223) are the worldwide record holders with a Cd figure of 0.22. The special simulation tools and the Mercedes-Benz aero-acoustics wind tunnel commissioned in 2013 make a decisive contribution to this. The EQS also received its fine-tuning there.
Extensive sealing and insulation measures reduce wind noise
In an electric car without the usual level of powertrain noise, wind noise is particularly noticeable by the occupants. That is why the aeroacoustic behaviour is particularly important. In this area, too, the new EQS is one of the very best vehicles in its class.
New solutions had to be found due to the concept-related lack of a partition between the interior and the boot and the aluminium alloys used in many places. Low-frequency noise, which can be perceived as reducing comfort, is prevented by filling numerous cavities in the body with acoustically effective foam.
It was possible to reduce the high-frequency components of the wind noise by specific measures on the door and window seals. Special attention was paid to the sealing of the transitions between the six side windows. The seals on the flush-fitting door handles, the window support and on the raised exterior mirrors are also noise-optimised.
A further contribution was made by the newly developed A-pillar with a specially shaped piece of trim at the transition to the windscreen. The development is supported by both modern flow simulations and external noise measurements using a special microphone array in the wind tunnel. The A-pillar designed in this way not only improves the aeroacoustics, but is also important for a low Cd figure and in keeping the windows free of dirt.
For further enhanced quiet running, the standard Acoustic Comfort Package has been developed. This includes additional insulation measures in the interior. Optionally, there are acoustically effective laminated glass panels at the side and rear. The additional acoustic glazing mainly reduces the wind noises even further, but also does so for noises coming in from the outside (for example, tyre noise or passing/oncoming vehicles). Particularly on longer journeys or motorway journeys, the driver remains more relaxed and the passengers feel more comfortable as a result.
On the optional panoramic roof, various wind deflection measures (wind deflectors, covers and seals with optimised geometry) ensure a high level of quiet running despite the large opening area of the roof.
 Cd figure 0.20: EQS 450+ with 19-inch AMG wheel/tyre combination and AMG Line exterior (available in the EU from the end of 2021) in the SPORT drive program