December 31, 2008 Mercedes-Benz has released details of its new SLK roadster models ahead of an April 2008 release. With around 650 newly developed parts in all, the latest line-up is marked by new-look front and rear sections - the redesigned front bumper with a modified air-dam arrangement enhances the two-seater's distinctive arrow shape while at the rear, a diffuser-style lower section, trapezoidal exhaust tailpipes and the AMG-inspired darkened tail lights have been added. Interior modifications include a new instrument cluster, three-spoke sports steering wheel and improved audio and telematics systems while under the hood the supercharged four-cylinder and V6 engine options have been boosted in terms of output and fuel economy with the 265 kW/360 hp, 5.5-litre V8 powerplant retained for the SLK 55 AMG .
The four-cylinder powerplant in the SLK 200 Kompressor and the six-cylinder sports engine in the SLK 350 both offer substantially more power and torque according to Mercedes. The most notable change is the introduction of the fast-running V6 sports engine that develops 224 kW/305 hp at 6500 rpm – 24 kW (33 hp) more than its predecessor - and peak torque of 360 Nm at 4900 rpm - a jump of 10 Nm. The performance enhancements are the result of a higher compression ratio, a new intake manifold and an extensively modified valve train with the engine speed limit raised to 6800 rpm (though 7200 rpm is possible in short bursts with oil temperature and other engine parameters permitting). Attention has also been paid to the engine acoustics with an emotive, sporty note promised - particularly when decelerating. The SLK 350 also consumes less fuel than its predecessor - 29.7 mpg running and 30.7 mpg if the 7G-TRONIC automatic transmission is fitted. This also translates to reduced CO2 emissions, down 23 g/km to 219 g/km in the automatic version and dropping by 28 g/km to 227 g/km in the manual version.
Standard equipment for the three new SLK models includes a precise six-speed manual gearshift, while the SLK 55 AMG still comes with the 7G‑TRONIC Sport seven-speed automatic transmission fitted as standard. Optional extras available include a five-speed automatic transmission for the SLK 200 and the 7G-TRONIC seven-speed automatic transmission or, alternatively, the 7G-TRONIC Sport with shift paddles on the steering wheel for the six-cylinder SLK 280 and SLK 350 models.
A newly developed, mechanical direct steering system with variable steering assistance is also available as an optional extra (standard for the SLK 55 AMG). The system is designed to ensure that the steering gear ratio changes in tune with the steering angle. The ratio is indirect when the steering is in or around the central position so as to ensure excellent straight-line stability and, therefore, a high degree of assuredness when travelling at high speed. At a steering angle of just 5 degrees, the ratio starts to increase extremely rapidly and the steering feels much more direct. As a result, the number of steering wheel revolutions from lock to lock is reduced by around 25 percent if the new direct steering is fitted.
Along with sharper handling characteristics and swifter gear changes offered by the improved AMG SPEEDSHIFT 7G-TRONIC transmission, the new SLK 55 AMG - which is still the only V8 in its class - features a new apron with a black-painted cross strut and side air outlets as well as darkened projection-beam headlamps and larger exterior mirrors.
The vario-roof that transforms the roadster into a coupé in 22 seconds is retained throughout the line-up and standard-safety equipment includes head/thorax sidebags, adaptive front airbags and two-stage belt-force limiters. The roadster also comes with the option of the unique AIRSCARF neck-level heating system, which allows open-top driving pleasure all year round, even in winter.
All models include hands-free radio control with Bluetooth technology and a new media interface added to the glove compartment for integration of personal media players into the the vehicle's audio system's user interface. Mercedes-Benz is also offering the LINGUATRONIC voice-operated control system as an optional extra in the SLK-Class for the first time. A harman kardon® Logic7® sound system is also optionally available which promises a surround sound boost regardless of whether the vario-roof is open or closed.
Full pricing for the new-generation SLK will be confirmed early in 2008 but the SLK 55 AMG is can now be pre-ordered with a price tag set at 69,049.75 Euro (incl. 19 % VAT).