Mercedes-Benz SLK 55 AMG 2005 Review

BOTTOM LINE: No replacement for displacement.

The flagship of the SLK line-up, the SLK 55 AMG boasts some impressive stats. Built to bury BMW's Z4 and keep Porsche's all-conquering Boxster S honest, the roadster is the sole V8-engined car in its class and delivers cutting edge technology in the form of composite brakes and Mercedes' impressive seven-speed automatic gearbox.

Launched in 3.5-litre V6 form in 2004, the SLK is strictly a two-seater convertible. Extensively equipped with the all the 350's goodies and then some, its folding steel roof is (like the lesser models') a work of art. Not only does it fold away in seconds, it manages to ensure the car looks good, roof up or down.

The SLK 55 shares its 5439cc V8 with C 55 and CLK 55 models. Naturally aspirated, the engine records a healthy 265kW at 5750 rpm, with peak torque of 510Nm registered at 4000 rpm. That's enough mumbo to shift it from 0-100km/h in a claimed 4.9sec. AMG further claims the 200km/h mark in just 17.5sec away from standstill.

What those figures don't show is the in-gear abilities of the SLK 55. Coupled with the seven-speed autobox, the car accelerates hard seemingly at will from anything approaching sane speeds. No need to worry about the wheel-mounted manual shifts, just sink the right foot and let the adaptive box do its work.

CarPoint sampled the SLK during AMG's annual media drive on one of the best roads in SE Australia. Winding its way across the top of Australia, the bitumen in question links Australia's highest town (Cabramurra, not Nimbin) with the sleepy trout fishing village of Khancoban, itself a stepping stone to the all-tar Alpine Way. This is a road of steep descents, equally challenging climbs and plenty of corners that allow little in the way of margin for error.

On this sort of going the SLK 55 shone. The flexibility of the engine/gearbox combination lets the driver concentrate on positioning the car just so – no hardship given the car's precise nature and neutral handling characteristics.

With revised suspension settings and thicker anti-roll bars the SLK seems none the worse balance-wise for the installation of the bigger engine. Indeed, though the car doesn't have the tactile steering feel of, say, Porsche's Boxster, in isolation turn-in seems as eager as the SLK 350 and a notch up on anything the Z4 can deliver. And while big bumps are transmitted, the ride was surprisingly supple - even on its l-o-w profile 225/40 (front) and 245/35 (rear) rubber. Just how it compares overall to the Boxster S will probably need back-to-back driving to decode.

And if ambitions get in the way of ability, there's them brakes! AMG terms its high-performance braking system as 'composite'. Don't confused this with ceramic composite, however. In the case of the SLK, the 340mm diameter ventilated front rotors are cast iron, but are mated to an aluminium centre via a sliding bearing that allows for both axial and radial movement. According to AMG the combination of these discs and the large pad surfaces of the six-piston front callipers ensure "outstanding thermal resistance coupled with optimum deceleration".

In practice, unlike lesser Benzs and, say, the C 55, the SLK 55's brake pedal stays high and yields immediate and spectacular bite -- time after time.

The SLK includes a full suite of driver aids. According to AMG, Electronic Stability Program (ESP), traction control (ASR) and Brake Assist, have been optimised for sporting drivers. Indeed, we left the 'off' button alone and found the only time it intruded on fun was when we were being deliberately ham-fisted out of some second-gear hairpins.

What we did do was drop the lid and enjoy the full volume of the SLK's sonorous exhaust note. Some reviews have commented negatively on the volume of the 55 - for our money the soundtrack's just right.

As you'd expect from a car with such sporting pretensions, it handled the Cabramurra-Thredbo thrash with aplomb. At the end the only evidence was the ticking of cooling brakes and a driver with a smile a mile wide. Exploring the limits of this AMG's performance needs a racetrack or a driver with much bigger cojones than yours truly.

Menacing... That's the word that springs to mind when you first spy the ultimate four-door AMG. I guess the impression is magnified when the car in question is presented black on black – paint, upholstery, dash, windows - right the way down to the 19-inch alloys and infeasibly low profile tyres.

The $435,900 S 65 AMG is the choice of F1 drivers and Russian mafia alike. Equipped with every conceivable optional extra (even the rear seats are electronically adjustable and heated and cooled) it's the ultimate expression of the German performance limousine – at least until AMG gets its hands on a Maybach.

Rational evaluation of this car is pointless. For a start, the numbers generated by the hand-built twin-turbo 6.0lt V12 powerplant are hard for us mere mortals to comprehend. Producing 450kW and an astonishing 1000Nm of torque, the S 65 boasts close to three times the power and torque of the base model Mercedes S 350 – itself no slouch. Unfettled this car runs to a rumoured 192mph! That's over 310km/h... Only Mercedes corporate sensibilities keep the AMG car electronically-limited to 250km/h.

Leave the traction control in place and the 5.2m-long 2.6-tonne behemoth sprints to 100km/h in less time than it takes to read this sentence – 4.4sec in fact. Turn the traction control off and you'll consign the rear 275/35 ZR19 hoops to the recycler in about the same length of time.

Floor the throttle at any speed under 200km/h and you'll experience the sort of acceleration most cars reserve for traffic light grands prix. If the engine (voted International Performance Engine of the Year in 2004) needs to kick down the five-speed autobox it's barely noticeable – instead you're concentration is firmly fixed front and centre. Better make sure there's plenty of room in front if you're intending to let this car stretch its legs.

The sheer pace of the S 65 AMG is intoxicating, but needs to be treated with a double dose of respect. Such is the in-gear flexibility and effortlessness of the performance that it's easy to arrive at the next corner with 30, 40 or 50km/h more in hand than is prudent. Fortunately the car's underpinnings are super-sized to cope. The S 65 AMG (and sistership CL 65 AMG) is equipped with Active Body Control (ABC) and bespoke AMG suspension with firmer damping and Mercedes' composite brakes – 390mm in diameter at the pointy end and gripped by eight (!) pistons.

ABC utilises 'smart' suspension components to limit body roll and pitch. Best to leave it switched on too if you're intending to use any welly... Indeed, left to its own devices (literally) this is car is amazingly quick point to point. Pace takes its toll, however, after just one day of the recent AMG drive in the Snowy Mountains, the S 65's front tyres were all but shot.

We could write about the S 65 AMG's safety features, comfort, legroom, trick adaptive front seats, even the comprehensive audio visual package, but what's the point. Absolute power corrupts absolutely - who do I have to kill to get one...