The EQS: Aerodynamics

Less resistance for more range and a quieter driving experience: With a cd value from 0.20, the EQS sets a new aerodynamic benchmark for production vehicles. A great deal of attention to detail lies behind the very good aerodynamic and aeroacoustic performance.

The purpose-driven design with smooth underbody and mostly closed radiator shutter as well as the favourable basic shape were a good starting point for the flow optimization. With a great deal of meticulousness, the aerodynamicists work closely with designers of the EQS to achieve the new record cd value of 0.20. The frontal area of the EQS is 2.51 m2. This results in an effective air resistance from 0.5 m2.

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 tires with optimized geometry

• Aerodynamically optimized wheels in the dimensions 19, 20 and 21 inches

• Cooling air control system with innovative transverse lamella 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. Previously, the A-Class Saloon (V 177) and the S-Class (V 223) were the worldwide record holders with a cd value of 0.22. The special simulation tools and the Mercedes-Benz aero- acoustics wind tunnel commissioned in 2013 make a decisive contribution to this. It’s this wind tunnel where fine-tuning was done on the EQS.

Extensive sealing and insulation measures reduce wind noise

In an electric car without the usual level of powertrain noise, wind noise is particularly noticeable. 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-optimized.

The newly developed A-pillar also contributed to noise reduction 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 aero-acoustics, but is also important for a low cd value 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, tire 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.

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For more information:

Sinead Brown
sinead.brown@mercedes-benz.ca