Prueba: Mercedes SLS AMG

100hpero

ITL

30-jun-2010 21:36

Background.
The first thing anyone wants to talk about, of course, is the doors. Certainly, there is considerable excitement here at the return of the Gullwing Mercedes. And talk about them we will, discussing exactly how practical they are in real use. However, there is so much more to the new Mercedes-Benz SLS AMG than its show-stealing doors.
The SLS AMG marks the end of the collaboration between Mercedes and McLaren in road car production. Although, at £157,500, the SLS costs considerably less than the earlier joint-venture SLR, it is unquestionably that model’s replacement.

Unlike the McLaren-built SLR, the SLS has been developed entirely in house. And by ‘in house’, Mercedes actually means the tuning firm AMG, which became an official Mercedes department in 1990. This is the first time that AMG has been given a clean sheet to build a road car from the ground up, and one with the billing that it will be something altogether more serious than the familiar ‘big-engine-and-comfortable-Mercedes’ AMG recipe. The talk this time is of an all-out supercar.

Design.
If there is one concept that runs throughout the SLS, it is the meeting of old and new. Obviously the SLS’s styling has been heavily inspired by the past, and specifically the original 300SL Gullwing, but it is a shape that has been reinterpreted for the 21st century. We doubt anyone would mistake the SLS for anything but a brand-new car.
Whether its shape appeals is, of course, your decision; our only comment is that it is certainly a striking design. Part of its visual impact comes from the proportions, with that massive bonnet and rear-set cabin but also the SLS’s considerable width. At 1939mm, it is broader than an S-class.
Like the original Gullwing, the SLS uses a spaceframe chassis, which is constructed mostly from aluminium and weighs just 241kg.

Aluminium is again used for the majority of the body panels (including the doors), the exceptions being the side skirts, bumpers and bootlid, which are plastic, and the steel A-pillars. Don’t be misled by the SLS’s unadventurous layout of a large-capacity, front-mounted engine powering only the rear wheels; in its detail, much of the SLS is cutting edge. The engine – a 563bhp, naturally aspirated 6.2-litre V8 – is set sufficiently far back in the chassis that all eight cylinders sit behind the front axle. It also has a dry sump, allowing for a lower centre of gravity and improved oil circulation during high-load cornering.
A carbonfibre driveshaft (housed within an aluminium casing for protection) then connects the engine to a dual-clutch transaxle gearbox with seven forward speeds. Power is channelled to the road through a conventional mechanical limited-slip differential.

On The Road.
Before we first tried the SLS, we wondered how Mercedes could get away with using the same engine in its new £157,500 supercar as it does in the £52,435 C63. Because, in essence, both use the same 6208cc V8. However, the first time we found a straight long enough to let the SLS give everything it’s got in third gear, any such cynical thoughts were dispelled in an instant.
In liberating an extra 112bhp from the V8, Mercedes has uncorked a monster of an engine. Add to that the fact that the SLS is 110kg lighter than the C63 and you get an impression of just how much quicker the SLS is. A 0-60mph time of 3.9sec tells only half the story, because this reveals as much about the difficulty of launching a front-engined, rear-drive car as it does about its ultimate performance.
The more telling achievement is the 0-100mph time of 8.0sec, which is quicker than the SL65 Black Series. In comparison, a Ferrari 599 takes 7.4sec, but if you exclude the 599’s trick launch control and look at the 60-100mph time, the SLS is just 0.4sec slower. No question the SLS has genuine supercar pace.

Yet it is also very easy to drive. The gearbox – the same Getrag unit as that used in the Ferrari California – has four modes, and its most relaxed setting (Controlled Efficiency, as Mercedes calls it) shuffles its seven ratios to keep the revs low and the power manageable. A long, well modulated throttle pedal also helps.
Although moving through Sport and Sport+ to Manual increases the shift speed, in never feels quite as instantaneous as some other dual-clutch systems. That said, it certainly feels fast enough. Our only criticism is that although Manual prevents automatic upshifts and kickdown, it will not allow upshifts at low revs. For instance, fourth cannot be selected below 25mph, yet in Comfort it will routinely select sixth at this speed.
Nestling between the dials is a line of change-up lights. That’s useful, although it’s rather hard to miss when the engine is approaching its 7500rpm limit, such is the volume of the V8. One noise we could do without, though, is the tyre drone at motorway speeds.
It’s a mixed report for braking performance. On the road the standard iron brakes performed impeccably, with good pedal response and strong stopping power. At the track, though, they started to wilt after just three laps. Carbon-ceramic discs are optional and worth considering for regular track use, but with the trade-off of worse pedal modulation at slow speeds.
The SLS’s cabin may be reminiscent of other Mercedes, but it takes only one corner to realise that this Mercedes drives like no other. Two elements define why it feels so different.

The first is the steering, which, for a Mercedes, is incredibly quick. It’s just 2.5 turns lock to lock and yet the SLS retains a respectable turning circle of 11.9m. Some testers found the steering a shade too quick, especially on initial turn-in. However, others loved the directness. There is reasonable feel, too – more than you get in a Ferrari 599, less than in the best Porsches.
The second defining factor is just how torsionally rigid the SLS feels. Commit to a corner and there is a noticeable lack of flex from the chassis. You turn the wheel, the front end bites and, with almost no hesitation, the rear follows. If you can gel with the steering, this inspires huge confidence.
Unusually, the SLS has a passive suspension set-up. Within the double-wishbone suspension front and rear are anti-squat and anti-dive functions, but there is no adjustable damping. Given its one suspension setting, it covers the remit of road and track work relatively well. At low speeds the SLS is very firm, perhaps too firm for boulevard cruising, but it smooths out noticeably with speed. The flipside is that body movements and cornering forces are extremely well controlled.
In its styling and configuration, the SLS has a whiff of hot-rod to it. To an extent that is also true of the way it drives, but the SLS is the hot-rod formula polished to the nth degree. Our only criticism is that all the polishing has removed a little of the supercar soul. When you’re going hard the SLS can be an exhilarating car, but when you dial it back a notch the SLS feels ever so slightly undramatic.

Living.
Much of the process of getting into the SLS is dominated by those doors. Unlock the car and small handles automatically sprout from each door; they retract again when the car is locked or driven away. The doors themselves are surprisingly light, their movement assisted upwards by a gas strut. Entry into the car is then relatively easy, if not tremendously dignified. You have to step over a wide sill and down into the seat, while remembering not to bump your head on the way.
Which brings us to the gullwing doors’ most controversial aspect: that they are not electrically assisted. Mercedes argues, reasonably, that this would have added weight exactly where you don’t want it. But the fact remains that unless you’re relatively tall or long-armed, you’ll have to grasp the door handle on your way down into the seat. Which is not impossible, but certainly a test of dexterity.

With the doors closed, the cabin is surprisingly compact. That said, the seating position is good, with enough legroom for those over 6ft and a decent range of adjustment in the steering. Our car had optional carbon-backed sports seats that, by virtue of being manually adjusted, sit lower in the car and boost headroom. With the standard seats, headroom is decidedly tight.
Overall, though, while there is just about enough room (and storage) for a long journey, the feeling within the SLS is snug. And familiar. Tall sills and long bonnet aside, the view from the driver’s seat looks remarkably like that of any other Mercedes. For the most part, this means that it is easy to use, but we can’t help feeling that the SLS could do with a bit more sense of occasion. And although the centre console does feel cold to the touch, the silver-effect main dials look out of place in a car costing this much.

There are different ways of looking at the cost of ownership. Given that some elements of the SLS can be found in Mercedes models costing much less than £157,500, you might regard its price as optimistic. However, for the performance on offer, the SLS is entirely on the money. We’d advise caution with extras, though, which pushed our car up to £171,710.
In the short term, relative exclusivity should ensure strong residuals, and over the longer term it is forecast to perform in line with comparable cars.
Fuel economy is unlikely to be a huge consideration for SLS owners. What is likely to be of greater interest is that its 99-litre tank gives a range of 417 miles, based on our 19.1mpg average.

Veredict.
Apart from straight-line acceleration, the SLS entirely eclipses the SLR. As a package, it is so much more complete and appealing and, if not as fast, then certainly fast enough. Especially given that it is practically half the price.
The dynamics are especially well sorted. The SLS may prove  to be a little stiff for those who buy one simply to commute or pose, but no one can question the SLS’s ability to get around a corner remarkably briskly.
Technically, our only real grumbles are that perhaps ceramic brakes should be standard and that the doors, although flash, do hinder access and interior space. However, for all its objective accomplishments, we wish it were a little more emotive. The cabin probably best sums up the SLS: enough space, well equipped and soundly built, but oddly ordinary at the same time.