A whole series of refinements go into achieving these record figures each time. The following aerodynamic improvements, for example, are among those to feature on the new S-Class:

Furthermore, when it comes to compact models such as the new A-Class (2012, Cd=0.26), coupés such as the E-Class Coupé (2010, Cd=0.24), saloons such as the E-Class (2009, Cd=0.25), sports cars such as the SL (2012, Cd=0.27) and SUVs such as the M-Class (2011, Cd=0.32), vehicles in these segments have never before achieved such low Cd figures.

An overview of the key aerodynamic figures for the entire Mercedes-Benz passenger car range:

BEE = BlueEFFICIENCY Edition Model, ¹ Saloon/Coupé/Estate,

² Saloon/Coupé/Estate/Cabriolet, ³ Coupé/Shooting Brake, 4 Coupé/Roadster
  

Models from Mercedes-Benz also take the lead in almost all segments when it comes to aeroacoustics. The new S-Class, for example, offers the lowest level of wind noise of any vehicle on the market.

To reduce high-frequency wind noise, the sealing system for the windows and door handles has been considerably improved. In addition, the new exterior mirrors and correspondingly designed A-pillars with a minimised upstand for the carefully directed drainage of dirty water prevent the air flow from separating at these points, and therefore noises that might penetrate into the interior via the windscreen and side windows. The roof structure and the sliding sunroof module have been aeroacoustically improved to benefit noise comfort in these areas too. In the case of the panoramic sliding sunroof, multiple wind-deflection measures (wind deflector, covers and seals with the appropriate geometry) ensure the same high level of noise comfort as in the preceding model, despite the larger aperture. The sum of these measures enables the new S-Class to meet its aim of being the quietest car around.

A subdued, scarcely perceptible level of noise in the interior of the S-Class was the objective when configuring and coordinating the sound insulation measures. Particular attention was paid to transmitted engine noise and road roar. During the acoustic optimisation work, the focus was both on lowering the sound pressure level and on achieving the well-balanced and comfortable overall sound perception that is a hallmark of the S-Class.

To ensure that engine noise is perceived as refined and unobtrusive in the interior, the firewall insulation was extended into the side areas of the A-pillars. Additional sealing layers were also added in the form of high-quality injection-moulded components.

A major contribution to the reduction in transmitted engine noise was made by improved insulation in the transmission tunnel area, as well as a modular engine partition made of plastic. The different noise characteristics of the engines are taken into account by the use of different weights per unit area.

The electrically adjustable rear seats, available as an optional extra, are free-standing. High-frequency tyre noise has been reduced by means of a large area of insulation extending from the seat surface to the rear panel and parcel shelf. Breakthroughs have also been kept to a minimum. An intelligent air ducting system inside the parcel shelf allows the necessary ventilation, while also reducing the intrusion of noise via the parcel shelf. The textile underbody and wheel arch cladding have an insulating and absorptive effect which reduces high-frequency tyre noise in the interior.

Anti-soiling measures are another aerodynamic discipline – and another area in which the aerodynamic specialists at Mercedes-Benz have led the field for many years. Soiling can arise from rain, vehicles travelling ahead or from spray thrown up by the vehicle's own wheels. Keeping windows and exterior mirror lenses as clean as possible, and therefore having the best possible visibility under all conditions, makes a contribution to active safety.

In the wind tunnel the aerodynamic specialists optimise components with the help of a fluorescent liquid which makes the soiling clearly visible. The aim is to direct water away so that the side windows and exterior mirror lenses remain clean. This is influenced by the geometry of the A-pillar with its integral components and the geometry of the exterior mirrors and window frames, or trim strips in the case of frameless doors.

Take the example of the side windows: a series of minor geometric modifications to the mirror housing, detailed refinements involving seals, plus a special water runnel, all help to reduce the build up of dirt significantly. The standard set by Mercedes-Benz defines that within the so-called core visibility area, no spray, no trickles but only isolated drops of water should appear on the mirror lens.