The Mercedes SL is the template for the luxury GT roadster. Once again the Germans show how it's done. Jonathan Crouch checks out the improved V8 SL500 model.
Ten Second Review
If you want a Mercedes SL, you probably want it with a V8 beneath the bonnet. The mst accessible option in this regard is the SL500 version, lately improved, with power uprated to 455bhp, that grunt marshalled by a freshly-developed 9-speed auto gearbox. There can be few complaints as to the engineering on show here.
This seventh generation SL has seen a rejuvenation of this model line - and it needed just that. The previous version was merely a mild update of its prededessor, so prior to this MK7 model's original launch in 2012, SL fans hadn't seen anything genuinely new for a very long time. This car has certainly delivered that with its light aluminium architecture. And it's perhaps at its most appealing in V8 SL500 guise. After all, the tuned top-of-the-range AMG models require lottery-winning money, while the base SL400 variant is V6-powered: enough said. You can see then, why someone would choose an SL in this form. And enjoy the many changes now made to this revised version.
It would be tempting to think that a car in this class doesn't have to be that good to drive; that it just needs a powerful engine and a modicum of refinement. This is Mercedes though and the depth of engineering verges on the neurotic. For instance, the steering knuckles and spring links on the front axle are also made out of aluminium to reduce the unsprung masses. The same also applies to virtually all the wheel location components on the rear axle. It doesn't stop there. The SL is offered with either semi-active adjustable damping as standard or there's an optional active suspension system ABC (Active Body Control) available as an alternative. Both suspension setups are teamed with an efficient electromechanical Direct-Steer system. Engines? Tick that box. The new 4.7-litre V8 in the SL500 now develops 455bhp, there's 700Nm of torque and you access it all through a freshly-developed 9-speed 9G-TRONIC auto gearbox. Across the range, SL drivers benefit from 'Dynamic Select' adjustable damping, a set-up you can tweak via 'Eco', 'Comfort', 'Sport', 'Sport Plus' and 'Individual' modes to suit the mood you're in and the road you're on. Another option is 'Active Body Control' with a curve tilting function. This reduces body movement through the bends in a way that's almost eerie. Acceleration? Well 62mph is just 4.3 away. Dynamically, this car has always sat rather uneasily somewhere between a Porsche 911 Cabriolet and a BMW 6 Series, not as sharp as the 911, not as luxurious as the Six. With this sixth generation SL, the difference is fundamental. In this, thanks to lighter weight, a wider track and the clever semi-active adaptive damping, we no longer have a car that's neither one thing or the other but one instead, arguably able to offer much of the best of both worlds.
Design and Build
Let's start with the fineries of fashion - classic SL proportions that have evolved through six generations and nearly half the history of this famous brand: the long bonnet, the compact passenger cell set well back within the wheelbase and a muscular, racy-looking tail. Changes to this improved MK6 model include a re-sculpted radiator grille that harmonises with the now standard AMG bodystyling. Two powerdomes on the bonnet invoke the sporting heritage of the SL, while light-catching contours give additional structure to the bonnet. Also adding to the revised appearance of this SL is the standard-fit LED Intelligent Light System with its headlamp housing extending far to the outside and an integrated torch-shaped unit comprising the daytime running lamp/position lamp and direction indicator. The side view of this SL reveals enlarged cosmetic air outlets with wing-like chrome inserts in the dynamic, broad vehicle wings. But it's what you can't see that's important here. 'SL' may stand for 'Sport Leicht' but historically, this model has always been something of a sporting heavy hitter. That changed when this sixth generation version first arrived in 2012 and the decision was made to construct the car entirely from aluminium. Of course, this car could have been a lot lighter still if the designers had dispensed with the bulky electrically operated Vario metal folding roof that only Mercedes now provides in this segment. It eats into boot space and makes it impossible for this car to offer the pair of occasional rear seats you'll find in competitors from Jaguar, BMW and Porsche but it's also one of the things that most appeals about this car to city-based buyers. The mechanism is still slower than a fabric hood would be but in this model has been speeded up to raise or lower the elaborate metal panels in a respectably rapid 20 seconds. And it can now be used at speeds of up to 25mph. When up, if you've specified what Mercedes calls 'MAGIC SKY CONTROL', you'll get a neat system that uses electro-reactive particles to switch the roof panel from light to dark at the press of a button.
Market and Model
You're looking at around £85,000 to own an SL500, a premium of around £10,000 over the entry-level SL400. As for rivals, well, a BMW 650i would cost £10,000 less to buy - but is also, we'd say, more than £10,000 less desirable. SL500 buyers also might be looking at a Maserati GranCabrio 4.7 V8 - but that requires a £100,000 budget. What you're paying for here of course is advanced hi-tech cleverness, two examples of which debut on this SL. Let's start with 'Magic Vision Control', billed as an intelligent and efficient wipe/wash system. The washer fluid jets out of the wiper blade directly in front of the blade lip, in both directions of wipe. As a result, no water is splashed onto the windscreen during spraying to disrupt the driver's visibility, and you'll never fire it onto your passenger when the roof is down. You can even specify a heated wiper blade to prevents snow or ice forming on it in winter. The other feature that speaks volumes of Mercedes' lateral thinking was the Frontbass system which utilises the free spaces in the aluminium structures in front of the footwell as resonance spaces for the bass speakers. This gives the SL's stereo a punch while freeing up space in the doors and saving weight. Clever.
Cost of Ownership
Mercedes SL buyers tend not to sweat the details of running costs too much, but for what it's worth, the fuel economy of the latest range has improved. This SL500, for example, returns 31.4 mpg on the combined cycle and a CO2 figure of 205g/km, making it considerably cleaner and more economical than its predecessor. That's thanks to the benefits conferred by an adjustable radiator shutter, an eco-gearshift programme for the 9G-TRONIC transmission, intelligent alternator management and a start-stop system that cuts the engine when you don't need it, stuck in traffic or waiting at the lights. This being a new model in a line that tends to go beyond the normal vehicle design life cycles, it's fair to say that depreciation will be better than the class average. That's not saying too much when rivals such as the BMW 6 Series convertible and Aston Martin Vantage Volante both suffer quite harsh residuals, but it is offset by the fact that SL owners tend to offset depreciation somewhat by owning their vehicles for longer than average and thus also enjoy the benefits of the less vertiginous section of the car's depreciation curve.
Those traditionally sold on the charms on a Mercedes SL will certainly be sold on this SL500. They'll certainly like the look of it thanks to the lithe proportions and deft detailing. Removing weight from the chassis, as Mercedes have here, is absolutely the right thing to do, as is concentrating on improving efficiency under the bonnet. Like its predecessors, this improved sixth generation SL offers a unique, fascinating and in some ways contradictory interpretation of sportscar motoring. It's not really suited to a track, yet it's more than just a very grand GT, a combination that won't suit if your preferences lie at either of these extremes. For many though, this will be the perfect way to reward themselves for a lifetime's endeavour.