Mercedes-Benz has moved down in the world – from a very expensive exotic car in the SLR McLaren to the more affordable new
Mercedes-Benz SLS AMG supercar . The SLS AMG is priced at about $230,000 against $450,000 for the SLR McLaren with its exotic carbon fiber hull.
But the SLR AMG does not lack performance – it races to 60 mph in 3.7 seconds, and can run up to 197 mph (317 km/h), to which it is limited. This is really bizarre because you can only reach that speed on a track really, and the car will not go much faster anyway.
Latest 6.2 liter V-8
Heart of the SLS AMG is AMG's latest 6.2 liter V-8 engine, mounted just behind the front wheels. They say this is virtually a racing engine, in the way it responds to the throttle, and in weighing less than the previous version of this V-8. The other innovation for Mercedes is the use of an aluminum frame – the company has used some aluminum in its structures before, but this is the first full aluminum frame.
And gull wing doors
Not surprisingly, Mercedes wants to associate the new car with the amazing gull-wing 300 SL of fifty years ago, so it takes some styling cues from the oldster, including the gull-wing doors which are reckoned to be more practical than the long normal opening doors you would have on a car of this type, or vertically opening doors which must go very high.
These doors are actually fairly practical, as they only go up to a height of 60 inches (1.50m) when fully open. On the other hand, you still have to duck under them.
Although the V-8 engine is fairly compact, this new Mercedes has a very long hood – not quite so extreme as on the SLR McLaren, and the wide frontal grille with big three-pointed star in the middle. There are grilles beneath each headlamp, and three more shallow grilles in the front skirt.
The car looks its best from the front. From the side the SLS AMG looks rather ordinary, but purposeful. This is because of the long, tall nose and small rear window with heavy rear quarters, and downwardly sloping tail. There are large flared air outlets behind the front wheels which relieve the dull sides a little. In fact, it looks very Teutonic, which is what you would expect.
At the rear, there is quite a small wing which is flush fitting normally, but which comes up at 75 mph to provide more downforce. Of course, there are the usual diffusers at the rear – neatly built into the rear skirt, and flanked by the rectangular exhaust outlets.
Lightweight owing to aluminum frame
Below this body is the aluminum frame, which consists of extruded rectangular members joined together with castings – as on the Audi space frame cars – and with all aluminum panels. To increase roll-over strength, the windshield pillars are steel.
Thanks to the aluminum frame, the SLS AMG supercar is much lighter than the SL models, with a kerb (curb) weight of 3,568 lb (1,620 kg). More surprisingly, it is 300 lb (136 kg) lighter than the slightly longer SLR McLaren with its over-engineered carbon fiber hull. Quite a bit of the weight reduction is in the engine and transmission, though. Therefore, this new Mercedes has an excellent power-to-weight ratio of 350 bhp per tonne (335 bhp per tonne with the driver aboard).
Sporty aluminum wishbone suspension
Helping to reduce the weight are the aluminum wishbone suspension, front and rear, which are designed to reduce brake dive and squat under acceleration. Also, the large castor angle gives plenty of feel through the steering and also increases negative camber on the outer wheel when cornering.
Without doubt, the Mercedes-Benz SLS AMG can be expected to handle very well, and with carbon-ceramic discs, the brakes will give all the stopping power you might need with this supercar. To give plenty of grip, 265/35 section tires on 19-inch wheels are fitted at the front, and 295/30s on 20-inch wheels at the rear.
There are the usual electronics, with three modes of operation of the stability control.
Torque tube to rear-mounted gearbox
The layout of the power train is similar to that of the current Aston Martin range, with the engine mounted well back, and power being taken through a torque tube and carbon fiber propeller shaft to the rear-mounted gearbox. This unit has been developed from the AMG seven-speed automatic, but has dual multi-plate clutches to give a smooth take-off from rest instead of a torque converter. They also allow full torque gear shifts as with the Porsche and Ferrari twin-clutch gearboxes which are different internally.
Inside, there is a compact LED instrument panel, lightweight seats offering plenty of lateral support, and there is also a reasonable amount of luggage space.
Clearly, the Mercedes-Benz SLS AMG is a welcome addition to the supercar ranks, and combines power and light weight in a front-engined car, which is a more practical arrangement for supercars that are used regularly, and not just for the occasional trip and track day.
