Mercedes-Benz SLS 2011 review

THERE'S an old chestnut about Formula One cars generating so much downforce that they could drive upside down if they went fast enough. The idea inspired a stunt by British TV show Top Gear, using a tiny Renault, and a more convincing effort by Mercedes-Benz, scoring big hits on YouTube, featuring its latest sportscar.

The footage shows the SLS racing into a tunnel, up a ramp on to the walls, over and down the other side for a complete 360. Local executives say the stunt, a sort of upmarket viral ad for the SLS, was done without special effects. The Germans found a suitable venue in the US and calculated that the SLS would need to hit 148km/h. At the end the driver is revealed as Michael Schumacher. Perhaps he's not past it after all.

Even without this sort of stuff, the SLS is the sort of car unlikely to escape notice. It is based on one of the most famous Mercedes models, the 1950s 300SL Gullwing, which helped re-establish the brand's reputation after World War II. Named for its dramatic roof-hinged doors, a racing version spawned a production car that was the fastest in the world in its day and which has become a collectible classic.

The SLS aims to harness that heritage and re-establish Mercedes credentials in the top division. Its previous supercar, the $1 million SLR, failed to win buyers despite blistering performance. Built by McLaren in Britain only in left-hand drive, it never achieved its 500-a-year sales targets.

This time Mercedes handed the project to its captive tuning house, AMG, which in the SLS has developed a model from scratch for the first time. Half the price of the SLR, the SLS aims to sell 10 times as many -- 5000 a year -- with right-hand drive markets such as Australia about to get deliveries.

Design

The original Gullwing doors were forced upon designers because normal doors were incompatible with the 300SL's tubular structure, or spaceframe. Since it's built in a similar way, the SLS might have encountered the same problem. But it didn't. Mercedes set out to re-create those doors in what is the first retro supercar.

As well as those happy apertures, the curves of the new car are a modern echo of the 300SL. What it lacks in originality it makes up for with stunning road presence and some great angles. It's wider than you expect, at almost 2.3m taking in the wing mirrors, but also lower and shorter. At 4.6m, it's not even as long as a C-Class, the junior executive Mercedes sedan.

The layout is pure race car: a naturally aspirated V8 mounted behind the front axle, transmission at the rear axle for balanced weight distribution, and double wishbone suspension all round. The engine is a reworked version of AMG's stock 6.2-litre item (badged as 6.3), with dry sump lubrication and 120 new components lifting output to 420kW. It drives through Mercedes's first double-clutch transmission with seven ratios and five levels of shift aggression.

Almost the entire car is made from aluminium, with some magnesium and carbon fibre components. Only 4 per cent is steel, concentrated in areas which need extra strength such as the windscreen pillars. So the SLS tips the scales at a relatively modest 1620kg, or nearly 150kg less than the carbon fibre SLR.

Although the SLR's supercharged 5.4-litre V8 develops another 40kW and 130Nm, these are negated by its extra mass. The two cars record identical zero-100km/h times -- 3.8 seconds. And the SLS goes on to hit 317km/h.

Braking performance on the SLS is no less impressive, with stopping distance from 100km/h a mere 32m. That's without carbon ceramic brakes, which are an option along with bucket seats, extra carbon fibre trim and a new paint finish called Alu-beam, which looks like liquid metal. Tick all the boxes and the on-road price can reach $600,000 -- that's in Ferrari territory.

Technology 

Notable absentees from the options list or spec sheet are adaptive suspension, active anti-roll bars and myriad technologies designed to enhance a car's dynamics that are now commonplace at this level. With the SLS, Mercedes has adopted a traditional approach that relies on the quality of the engineering and components. If you want firmer springs and dampers, then the sports suspension must be ordered from the outset.

That's not a decision to be taken lightly. Even Mercedes acknowledges that the sports suspension is best avoided unless the SLS has been bought for track days, where it can make the most of a smooth surface. On the drive event in NSW one of the three cars available was fitted with sports suspension, and that's the car I drove first. On Australian roads, it's impossibly firm.

It may have coloured my view of the standard suspension, which felt like blessed relief by comparison, because others were grumbling about it. The softer set-up retains disciplined control of the body -- the long bonnet lifts just a little under a firm throttle -- but overall composure is much better on torn-up country roads for both ride and handling. There's nothing lush about it, but it is recognisably a Mercedes.

Driving

In the absence of active dynamic systems, the drive experience is accessible and engaging at any speed. Mercedes says the SLS is an easy-to-live-with supercar that can be used ever day.

But it's more than that. The chassis, steering and brakes keep the driver in touch with the car even on a gentle commute. The engine is constantly engaging too, with one of the best V8 soundtracks around. It is a lazy, slow rumbling that has something in common with American muscle cars. I found myself tickling the throttle unnecessarily at low speeds just to trigger a bit of chortling over-run.

So slow speeds in the SLS aren't anaesthetic and glimpses -- only glimpses, unfortunately -- suggest that it has plenty of higher pace potential, with excellent stability and ultra-quick turn-in to corners. The SLS feels like a balanced result next to some AMGs, which deliver more power than dynamic ability.

The automatic gearbox was a standout, anticipating the need for shifts with precision, and I left the paddle changers alone most of the time. They sit behind an attractive steering wheel in one of Mercedes's better recent cabins. The seats are first-rate and there's a surprising amount of room thanks to the car's width. In a clean design, leather covers almost everything but pleasing details, such as the vents, are rationed. The thick A-pillars have been cleverly shaped so that they don't obstruct forward vision, and it is easier to see out of the SLS than many other supercars.

If there's a let-down, it's the dreary centre console arrangement of buttons, the same layout as in every Merc. It looks cheap. The car wasn't free of creaks and groans either, and while these are common enough in super-rigid supercars, one or two pieces of loose insulation rubber suggest Mercedes was still finessing production when the launch examples were built. The doors would certainly present special difficulties to an assembly line.

Thanks to those doors, the 300SL also had a reputation for being difficult to get into, with wide sills and low seats compounding the awkwardness. Happily, the SLS presented no such problem to this average-height driver. It's a slight stretch to reach a door handle when it's open, but the action is light and I quickly got used to stepping out without banging my head.

The doors need less space alongside the car to open than the long doors on most coupes, although I did wonder about low garage ceilings.

Read more about prestige motoring at The Australian.