Stuttgart, Germany, Mar 08, 2010

The roof: Exemplary quiet-running

- Quiet: acoustic soft top as standard for all versions
- Safe: exceptional all-round visibility thanks to slender C-pillars
- Hard-wearing: soft top can be put through an automatic car wash without hesitation

Thanks to its acoustic soft top, fitted as standard, the E-Class Cabriolet has one of the quietest interiors in the segment for four-seater premium cabriolets with a fabric roof. The soft top's exceptionally high-quality insulation brings about a clearly noticeable reduction in the interior noise level compared to conventional fabric soft tops. Exterior noise caused by other vehicles and wind noise are therefore absorbed more effectively. On the road, the difference is audible from speeds of just 80 km/h, for example when driving through a tunnel or overtaking a convoy of trucks. At higher speeds, the benefits of the acoustic soft top are even more tangible. For instance, it is possible to have a perfectly normal phone conversation in hands-free mode even when travelling at a speed of over 200 km/h.

Three new developments enabled the Mercedes-Benz engineers to reduce the
interior noise level substantially: the outer fabric coating on the soft top has been acoustically optimised, while a butyl layer in place of the previous neoprene layer on the inside acts as a water barrier. Finally, the intermediate felt layer is structured differently to that of the previous model. This layer also ensures that the elegant silhouette is not disturbed by bows visible from outside.

The E-Class Cabriolet likewise sets new standards when it comes to all-round visibility – important for both looks and safety. The soft top fabric in the C-pillar area‑is extremely slender thanks to the sophisticated kinematics of the rear windscreen which, rather than being rigidly fixed in place, moves out of the soft top fabric when the roof is opened and closed. Special water pockets prevent moisture ingress at the sides.

Of course, the soft top itself is also waterproof and windproof. Plus it can be put through an automatic car wash without any hesitation. With a total thickness of 23.5 millimetres, the fabric soft top offers excellent thermal insulation, meaning that the E-Class Cabriolet is also ideal for use in winter. The heated rear windscreen is made of glass and is therefore scratchproof. The soft top is available in black, blue or beige.

Supreme ease of use was a key criterion when developing the soft top, which is hydraulically operated by means of seven cylinders pressurised by an electric pump. Fully automatic opening and closing of the roof takes around 20 seconds and is possible at speeds of up to 40 km/h. A pull on the control on the centre tunnel is all it takes. Alternatively, the roof can be controlled remotely by pressing a button on the key. The soft top engages automatically at the front roof crossmember.

The soft top is stowed in a special compartment behind the rear panel. A retractable cover separates the soft top compartment from the boot area; it must be
closed in order to close the soft top. If the roof is to remain closed, the cover can be slid rearwards, in which case the boot capacity is increased by 90 litres to 390 litres.

Differences between the exterior and interior air pressures can cause a ballooning effect on certain cabriolet models when travelling at high speed. But not in the case of the Mercedes-Benz E-Class Cabriolet: a special zip fastener is used to fasten the soft top firmly to the frame over all three bows. This fastening and the short fabric lengths between the supports are effective at preventing ballooning of the roof when travelling at high speed. Sophisticated test equipment was used to measure and document this effect during the road-testing phase.

The cabriolet specialists at Mercedes-Benz also attach great importance to the
durability of the fabric soft top. Hence the roof is designed for 20,000 load cycles – the highest figure in this competitive environment – equivalent to opening and closing the soft top once on every day of the year for over 25 years. In the unlikely event of the fully automatic closing mechanism failing, for example due to a flat battery, Mercedes-Benz has seen to it that E-Class Cabriolet drivers will not be left in the rain, since the hydraulic system can be depressurised quickly, enabling the soft top to be closed and locked by hand.

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