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Direct-steer system: consummate sporty driving pleasure

The SL name is synonymous with driving pleasure as well as design. These Mercedes sports cars have always offered a scintillating driving experience that does not deal in compromises - neither in terms of handling dynamics nor by any means when it comes to comfort or safety. It was under this premise that the Mercedes engineers modified and perfected the SL technology, one example being the new, optionally available direct-steer system, which is as simple as it is ingenious and provides a whole new driving experience when cornering.

This new development is based on the familiar standard-fit speed-sensitive power steering system with lower steering forces - the benefit of which is noticeable above all when driving slowly, manoeuvring or parking. New features include a variable rack ratio, which adjusts in line with the steering angle, increasing sharply as soon as this reaches five degrees. All of which means that, compared to a steering system with a constant ratio, the driver does not have to move the steering wheel as much when cornering. The car's response is therefore noticeably more direct, allowing the driver to steer more spontaneously or, in other words, more sportily.

When driving slowly or parking, the new technology combines with the speed-sensitive power steering to provide even more comfort than before because the large ratio further reduces the steering effort required.
In addition, the SL still offers some of the very finest chassis technology available in the shape of four-link front suspension and multi-link independent rear suspension. Meanwhile the Active Body Control (ABC) system, specified as standard for the SL 500 and the SL 600, is a unique masterpiece. It compensates pitch, roll and yaw on the part of the body and adapts the suspension settings automatically to suit the current driving situation. This makes for excellent agility on the one hand and optimum driving stability on the other, without compromising the car's super levels of comfort. Mercedes Benz has further fine-tuned the ABC shock-absorber settings for the new-generation SL in order to bring a whole new quality to this unique blend of sportiness, comfort and safety.

Size 255/45 R 17 wide-base tyres and 17-inch light-alloy wheels are fitted as standard on the new SL 280 and SL 350 models, whereas the V8-powered SL 500 Roadster runs on 18-inch wheels shod with 255/40 R 18 tyres. And the exclusive character of the twelve-cylinder SL 600 model is accentuated by 18-inch ten-twin-spoke light-alloy wheels with 255/40 R 18 tyres at the front and 285/35 R 18 tyres at the rear.

Engines: new, extremely sporty six-cylinder powerplant

Mercedes-Benz is extending the SL-Class line-up by introducing an attractive entry-level model in the shape of the SL 280 developing 170 kW/231 hp. The six cylinder powerplant delivers its peak torque of 300 Nm from 2500 rpm and accelerates the roadster from 0 to 100 km/h in 7.8 seconds, whilst fuel consumption (NEDC) is just 9.4 litres per 100 kilometres.

For the SL 350, the Mercedes engineers have developed a V6 powerplant that brings the sporty qualities of the new SL generation right to the fore. The term "sports engine" could not be more apt: through a process of meticulous engineering, the Stuttgart specialists have further enlivened the temperament of the six-cylinder unit, enhancing its dynamic response dramatically. The engine responds instantaneously to movements of the accelerator pedal and can rev up to 7200 rpm in order to make full use of its power reserves in certain driving situations. Compared to the previous 3.5-litre engine, the output has been boosted by 16 percent to 232 kW/316 hp (at 6500 rpm), while the peak torque has been increased by 10 Nm and now stands at 360 Nm. This powerplant accelerates the new SL 350 from 0 to 100 km/h in a mere 6.2 seconds, making it 0.4 seconds faster than the outgoing SL 350.

In this case, however, the extra power does not come at the expense of fuel economy: with a consumption figure of 9.9 litres per 100 kilometres (NEDC), the new SL 350 undercuts the previous model developing 200 kW/272 hp by 0.4 litres per 100 kilometres.

The sporty character of the V6 power unit is also clearly audible. Its powerfully sonorous sound is the result of meticulous work carried out by sound designers. So these specialists also contribute to the sporty driving pleasure. In this respect, the standard-fit seven-speed automatic transmission also has an important role to play: on the one hand by allowing fast multiple downshifts when accelerating, on the other hand by providing a new double-declutching function that is activated during manual downshifts. As well as producing a sporty sound, this function also enhances comfort and safety as the double-declutching equalises the rotational speeds of the crankshaft and transmission. This set-up gives the driver the advantage of even more harmonious gear changes. Plus there is a noticeable reduction in load-change reactions.

The flagship engines in the SL line-up remain the eight-cylinder unit in the SL 500 developing 285 kW/388 hp and the V12 powerplant in the SL 600, which develops 380 kW/517 hp thanks to its twin turbochargers. The Mercedes engineers also worked meticulously on these models to further reduce fuel consumption by up to 0.4 litres per 100 kilometres.

Safety: lights for every driving situation, whatever the weather

For five decades, Mercedes sports cars have been setting the pace when it comes to innovative developments in active and passive safety for open-top cars: in the 1960s the SL was the first sports car to feature a safety body based on Béla Barényi's principle, while in the 1970s the SL pointed the way ahead with its three-point inertia-reel seat belts fitted as standard. These developments were followed by ABS and the airbag in the 1980s, while the automatic roll-over bar and the robust integral seats celebrated their world premieres in the early 1990s. The comprehensive range of safety equipment available for the Mercedes sports car was rounded off in 2001 following the introduction of innovations such as adaptive front airbags and head/thorax sidebags.

The new-generation SL continues this tradition, the main focus of the engineers' efforts this time being to improve driving safety at night and in fog. Hence the sports car is equipped as standard with powerful bi-xenon headlamps, which are considerably more powerful and more energy-efficient than comparable LED headlamps. In addition, the optionally available Intelligent Light System provides five different light functions designed specifically for typical driving situations and weather conditions: country mode, motorway mode, enhanced fog lamps, cornering light function and active light function. The variable-control bi-xenon headlamps activate the various light functions automatically. Motorway mode is activated in two stages when the speed exceeds 90 km/h, increasing the driver's range of vision by up to 60 percent.

When the active light function is activated, the headlamps pivot to the side in line with the steering angle when the driver enters a bend, allowing them to see around 25 metres further into a long bend than is the case with conventional dipped beam. The cornering light function is activated automatically at speeds below 70 km/h when the driver steers and/or indicates. This means that, as well as enhancing safety when turning at junctions or on slip roads, this light function is also active when cornering at low speed and improves illumination of the areas at the side of the carriageway. The enhanced fog lamps ensure better illumination of the verges, making it easier for drivers to get their bearings. The intelligent headlamp technology installed in the SL can therefore make an important contribution to road safety.
Source: Mercedes-Benz