New models - Mercedes-Benz - SLK-class - SLK55 AMG
First drive: AMG tunes Mercedes' little SLK
Mercedes' SLK drop-top receives an AMG dose of steroids
16 Mar 2005
By TIM BRITTEN
WE all kinda hoped Mercedes-Benz would pull something special out of the hat with its second-generation SLK. So far, we haven’t been disappointed. Even the base SLK200 is imbued with an on-road presence that says it is a quite different animal to the previous SLK.
That promise is truly fulfilled with the arrival of the AMG version – and the installation, for the first time, of a V8 engine in the pint-size, two-seat sports convertible.
We are talking here about 265kW, and a zero to 100km/h capability of 4.9 seconds – convincingly putting to rest any of the suggestions levelled at the previous SLK of being a hairdresser’s car (which it never was, especially in 3.2-litre V6 form).
The SLK55 AMG has been eagerly awaited since the second-generation SLK arrived last year, and not without reason.
As part of a stupendous AMG line-up, it imbues the car with close to devastating performance that is well matched by the inherent capabilities of the SLK chassis.
It all starts with the alloy V8 that does duty across the Mercedes range, from C-class upwards, bumped to the same capacity as the SL55 AMG exoticar that arrived here in 2002, but dispensing with the supercharger that would obviously have been going slightly overboard in this case.
With its 265kW and 510Nm required to push along a mere 1540kg, the SLK55 AMG was clearly never going to be in any trouble getting out of its own way.
Mind you, considering the technology in this normally aspirated V8, it’s actually understressed, operating well below what its true potential would be, even without supercharging.
If Holden can screw 260kW and 500Nm out of an only slightly larger pushrod V8, imagine what could be done with this engine if the engineers half tried. The supercharged version that is used in the E55 AMG produces 350kW and 700Nm, slightly more power (368kW), but the same torque in the bigger S55 and CL55.
In its relatively mild SLK state of tune, the short-stroke V8, with its compression ratio of 11.0:1, will rev to 6700rpm. Maximum power comes in at 5750rpm, while the 510Nm of torque are produced at 4000rpm.
AMG work includes aluminium pistons, composite camshafts and an adapted variable intake manifold that aims at extending the useful power band.
This meaty engine is hooked up to the relatively new Mercedes seven-speed auto transmission and there’s a heavily worked chassis with adapted front MacPherson struts, chunkier anti-roll bars and new gas shock absorbers. The rear 18-inch, multi-spoke alloy wheels run wider (8.5J) rims than the 7.5-inch wide front wheels and the tyres measure 225/40 at the front and 245/35 at the rear.
The braking is beefed up to contain the extra performance and uses ventilated composite 340mm discs with six-piston calipers at the front, and regular ventilated 330mm discs at the rear.
Other toughening up included the drivetrain, which was selectively fitted with heavier-duty components, and the differential, which is fitted with a heat sink that is able to drop oil temperature by as much as 15 degrees.
Externally, the AMG SLK is set apart from its more mundane siblings via a quite subtle AMG body kit mainly comprising new front and rear bumper mouldings, side skirts and a mini spoiler in the boot lid. The air intakes below the windscreen also have longitudinal raised fins that are visible from the interior so driver and passenger are reminded of what they are actually riding in.
Standard gear includes heated, leather-trimmed power sports seats, climate-control air-conditioning, satellite navigation, bi-xenon lights and a six-disc CD player in the glovebox. Options include the Mercedes ‘Airscarf’ neck-level heating, surround sound and a tyre pressure monitoring system.
All the expected Benz chassis electronics are there too, including stability control (ESP), traction control (ASR) and ABS with brake assist.
Mercedes-Benz expects to sell around 100 or so SLK55 AMGs a year in Australia in the initial phase of its introduction, but that figure will dwindle, as is usually the case with limited-volume high-end aspirational cars, once market saturation has been reached.
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