A CD factor of 0.22 is simply outstanding for a new car and this is achieved with a huge grill and big rear view mirrors. I remember 30 years ago their were a number of concept cars that were hitting CD's of 0.22 to 0.24.
With a Cd figure from 0.22*, the S-Class is one of the world’s most aerodynamic cars, and especially so in the luxury saloon segment. Although the frontal area (A) of the new S-Class has increased slightly to 2.5 sq. m., the drag coefficient has been reduced even further compared to the preceding model. The product of
Cd and A is 0.56 sq. m.
The S-class has a lower CD than the
Mercedes F100 Concept of 1991 which had a CD of 0,24 with its totally flush exterior windows.
Here are the cd values of selected Mercedes-Benz models from the period prior to the Second World War:
| Model | cd | A (m²) | cd × A |
| 260 (W 02) | 0.662 | 2.53 | 1.675 |
| 130 (W 23) rear-engine vehicle | 0.516 | 1.953 | 1.008 |
| 170 V (W 136) | 0.600 | n/a | n/a |
| 170 V (W 136) with aerodynamic body as developed by Prof. Dr.-Ing. W. Kamm (prototype vehicle) | 0.361 | 2.0937 | 0.7558 |
Measured with cooling-air flow.
With a cd value significantly below 0.50, the model 220 (
W 180) meets optimal conditions for better performance with lower fuel consumption thanks to more favourable aerodynamics, despite its larger body when compared with its predecessor.
| Model | cd | A (m²) | cd × A |
| 220 (W 180) | 0.473 | 2.07 | 0.9791 |
Measured with cooling-air flow.
Yet another advancement became clear with the introduction of the
W 111 model series in 1959. Compared with the “Ponton” (“pontoon”) W 180 model series, the drag coefficient had improved by 13 per cent. Despite a 3.86 per cent larger front surface area, the total aerodynamic resistance obtained by multiplying A by cd dropped by 9.7 per cent.
| Model | cd | A (m²) | cd × A |
| 220, 220 S, 220 SE (W 111) | 0.411 | 2.15 | 0.8837 |
In fact, the flatter roof and lower rear end of the
W 108 model series even resulted in a less favourable drag coefficient compared with the W 111 model series. Nevertheless the level achieved with the W 111 model series was essentially maintained: a 2.2 per cent higher cd value was accompanied by an 1.9 per cent decrease in front surface area, resulting in a nearly identical total resistance value from the combined front surface area and cd value.
| Model series | cd | A (m²) | cd × A |
| W 108/109 | 0.420 | 2.108 | 0.8854 |
The
W 116 model series, the first to be called Mercedes-Benz S-Class in official communications, achieved nearly the same values as the W 111 model series due to its high rear end and it scored a somewhat better in total resistance owing to its reduced front surface area.
| Model | cd | A (m²) | cd × A |
| 280 SE (W 116) | 0.412 | 2.14 | 0.8817 |
As with the transition from the “pontoon” W 180 model series to the “tailfin” W 111 model series, the changeover from the W 116 model series to the
W 126 model series marked not only a leap within the Mercedes-Benz model series; this S-Class also far outranked the international competition in its segment. The major optimising factors for a favourable drag coefficient were the sharper falling slope of the roofline, the high rear end with its rearward structure slightly tucked in at the sides, the steeper inclination of the windscreen (54 degrees), the recessed windscreen wipers, drip moulding integrated into the body, a stepless transition of the front wall pillars and a seamless transition from the bumpers to the body.
The success of all these measures was impressive: the cd value improved compared with the predecessor W 116 model series by 12.9 per cent – tops in the industry at that time. The front surface area decreased by roughly 1 per cent, and the total resistance by 13.3 per cent.
| Model | cd | A (m²) | cd × A |
| 280 SE (W 126) | 0.359 | 2.1283 | 0.7641 |
By introducing new measures, the engineers were able to decrease the drag coefficient of the
W140 by a further 16.4 per cent, thereby achieving a new record in this vehicle class. Although the frontal area increased by 12.2 per cent compared with the predecessor, (thus also earning it a new record in the comparison segment), this S-Class also had the most favourable total resistance value of all S-Class cars since the “pontoon” W 180 model series. This was made possible thanks to its drastically lower cd value. The W 140 beats the W 180 in this regard by 26.8 per cent and outperforms the legendary predecessor W 126 model series by 16.4 per cent. This fact is particularly astonishing given the car’s imposing overall appearance.
| Model | cd | A (m²) | cd × A |
| 300 SE 2.8 (W 140) | 0.30 | 2.39 | 0.717 |
When the
W 220 model series of the S-Class was presented in 1998, it again attained the top ranking in the luxury car class with a drag coefficient of 0.27. This value was achieved by a number of measures, in particular a slightly sharper slope of the front and rear windscreens, a boot lid with an integrated spoiler edge, a more tucked-in side body, a wheel spoiler in front of the front and rear wheels, a covered engine bay underbody, a sophisticated enclosure concept for the remaining underbody, and a speed-dependent vehicle lowering mechanism.
In connection with a 4.2 per cent smaller front surface area and 10 per cent lower cd value, the W 220 model series achieved a 13.8 per cent earning it a world record in this area at the time of its press launch.
| Model | cd | A (m²) | cd × A |
| S 280 (W 220) | 0.27 | 2.29 | 0.618 |