http://www.autocar.co.uk/contentImages//Car/Mercedes-Benz/SL/6588113639.jpg[/IMG]o.uk/CarReviews/RoadTestsHistory/Mercedes-Benz-SL-63-AMG/232567/]Mercedes-Benz SL63 AMG - Autocar.co.uk Mercedes-Benz SL63 AMG 
For Quick and clever gearbox, precise steering, thunderous engine note, slick roof
AgainstPatchy low ride speed, gearbox paddles, crass cosmetic add-ons
1. Background
New SLs do not come along very often. Since the model line’s 1954 inception, there have been only five generations.
The gullwing 300SL started life purely as a racing car, winning Le Mans in 1952, before its road-going variant was developed in ’54. That was replaced by the 300SL roadster in 1958; the cheaper 190SL was sold alongside these until they were replaced by the 230 in 1963. Further generations arrived in ’71, ’89 and 2001.
Road testing a Mercedes-Benz SL is always a special experience. Not only because the car’s legendary protracted life cycle makes it a rare opportunity, but also because the SL typically arrives decked out with some of the best in equipment, innovation and luxury that Mercedes has to offer.
The latest SL is a facelift of the fifth generation, produced since 2001, rather than an all-new model, but it justifies its inclusion here through the depths of the revisions – at least in the SL63 AMG guise you see here.
No other model in the facelifted SL range is more altered than this one. Chief among the changes is that the bruising old 5.4-litre supercharged V8 from the SL55 has gone, replaced by the much-liked 6.2-litre, normally aspirated V8 that AMG has been rolling out across many of its models since 2005.
We already thought the SL55 was a fine car. Can this one, with more power, a new gearbox and a revised chassis, be any better?
2. Design
SLs, typically, are styled with longevity in mind; few other cars retain their elegance over time as well as an SL. That’s probably true of the current range, although the SL63 may not prove quite so aesthetically enduring.
That’s not because of its basic shape (although the new-found aggression of Mercedes’ nose job does not entirely sit easily on the moderately curved body), but rather the AMG-specific details, which echo the look of this year’s F1 pace car. The carbonfibre wing mirrors and rear spoiler, not to mention a standard rear diffuser that does precisely nothing to reduce aerodynamic lift, somehow sit rather uneasily on what is, after all, a two-tonne luxury coupé/roadster.
Beneath that new nose you’ll find a 6208cc V8 engine – a technically brilliant unit, if not instantly as endearing as its supercharged forebear – which produces its 518bhp at 6800rpm and its 465lb ft of torque at 5200. It revs to 7200rpm.
It drives through a new transmission. The seven-speed AMG Speedshift MCT gearbox is largely a conventional automatic unit, but uses a wet clutch rather than a torque converter for improved response. In the cabin there’s a knob for choosing between four different drive modes – from Comfort, which acts as smoothly as possible, through Sport and Sport+ to Manual, with increasingly faster shifts each time.
The suspension consists of double wishbones at the front and a multi-link set-up at the rear. The SL63 has revised Active Body Control (ABC), a hydraulically controlled damping system that adjusts the pressure of fluid around a spring unit to minimise body movements. Its settings are further uprated if you add the £8230 Performance Package, which also brings a limited-slip diff, larger front brake discs and a different steering wheel.
Our test car was also fitted with a £2230 Driver’s Package, which includes a driver training course and raises the speed limiter from 155mph to
3. On the Road
While the SL63 has larger swept volume and greater peak power than the SL55, it would be easy to perceive it as a backwards step. The reason for this is its torque. Not only did the supercharged SL55 produce a whopping 516lb ft, but it did it from 2750-4000rpm. The best this naturally aspirated unit can manage is 465lb ft, and not until 5200rpm.
Set those preconceptions aside and the SL63 presents a very convincing case. When locked in fourth gear (possible only with the gearbox in Manual mode), 30-50mph takes 3.9sec, 60-80mph 3.5sec and 100-120mph 4.1sec. Which is good enough for us. Similarly, although peak torque doesn’t arrive until 5200rpm, at least 442lb ft is available anywhere between 3500 and 6000rpm.
With time you learn to trust the car, knowing that when a few extra revs arrive, so will the desired propulsion, and that if you’re further down the rev range the gearbox will summon a lower ratio.
The new seven-speed wet-clutch automatic does this with excellent judgement. When cruising, Comfort is the most refined gearbox mode, but for cross-country driving Sport+, which downchanges in preparation for corners, is the most satisfying mode.
Around town the ride is firm, bordering on uncomfortable. While the damping does an admirable job of containing the movement, with no bounce, the springs are so firm that every road imperfection is felt. Exceed 40mph, however, and the SL63 feels like a different car. Surface changes still reach the cabin, but not sufficiently to disturb, and the faster you travel the better it becomes.
It is in body control, though, that the SL63 impresses most. Even on our most extreme test route, the SL soaked up compound bumps with ease. Comfort is best, but even in Sport the SL never loses its composure.
For what is ostensibly a cruiser, the SL delivers a remarkably satisfying drive, the chassis sweetly balanced and controlled through excellent steering.
4. Living
Although it still feels natural enough to lament the passing of the SL55, there’s no denying the SL63 is a better car in almost every respect. The engine is extremely flexible and is finally matched to a gearbox whose response and intellect allow its potential to be fully exploited. The drivetrain is so good that, rather than notice that there is less torque than before, you simply find yourself in the right gear more often.
The rest of AMG’s take on the SL remains similarly impressive, so long as you know what to expect: the gearbox’s abrupt step-off and the unsettled low-speed ride mark this car out more as a sports car than a boulevardier. But the SL has retained its ability to crunch through miles with the minimum of fuss.
Being picky, we’d like it to use less fuel and cost less to buy, but even with these things taken into consideration it is excellent.
5. Verdict 
Although it still feels natural enough to lament the passing of the SL55, there’s no denying the SL63 is a better car in almost every respect. The engine is extremely flexible and is finally matched to a gearbox whose response and intellect allow its potential to be fully exploited. The drivetrain is so good that, rather than notice that there is less torque than before, you simply find yourself in the right gear more often.
The rest of AMG’s take on the SL remains similarly impressive, so long as you know what to expect: the gearbox’s abrupt step-off and the unsettled low-speed ride mark this car out more as a sports car than a boulevardier. But the SL has retained its ability to crunch through miles with the minimum of fuss.
Being picky, we’d like it to use less fuel and cost less to buy, but even with these things taken into consideration it is excellent.
