Mercedes SL63 AMG

An eye-watering price tag means the SL63 AMG needs to be very good to justify this victory. Great body control, sharp handling and a monstrous engine ensure it hits the mark. Plus, we think it’s just as desirable without the very expensive Performance Pack and ceramic brake optional extras.

Throughout its 60-year life span, the Mercedes SL has maintained a uniquely classy image. Yet from the curves of the original fifties model to the famous pagoda-roofed MkII and boxy MkIII, the shape has always changed with the times.

The new MkVI car continues the wedge- shaped theme introduced in 1989, and while its design is a little fussy, it’s unmistakeably an SL, with a long bonnet, clean profile and chunky rear end. The folding hard-top is neatly incorporated, while a magnesium-plastic frame means the roof’s 15kg lighter than before. It folds in less than 20 seconds to reveal a spacious and upmarket cabin.

Thanks to a huge range of adjustment, the supportive and comfortable seats wrap around you, while the sweeping dash and raked screen continue the cosy feeling of the SL’s cabin. Chrome-ringed dials and stylish air vents also add to the sense of occasion.

First-rate materials dominate the cabin, while Mercedes’ COMAND audio, navigation and car settings system is easy to use. The M6 is a match on quality, but the SL63’s modern interior highlights just how dated the Jaguar’s cramped cabin now feels.

Still, the SL does without the tiny rear seats of the XKR-S in favour of extra luggage space behind the driver and passenger. This is handy, as the Mercedes’ boot space drops from 504 litres to 364 litres when the roofis lowered – although that’s still 64 litres up on the same figure for the BMW.

However, it’s the exposed carbon-fibre inside the bootlid, rather than the luggage space, that’ll excite keen drivers. It’s a visible example of AMG’s focus on weight saving, which makes the latest SL also the first mass-produced Mercedes to be built almost entirely out of aluminium.

As a result, the SL63 is 125kg lighter than the previous car, yet there’s also been a 20 per cent increase in torsional stiffness. The improvements continue under the bonnet, where the all-new twin-turbo V8 engine produces 530bhp and 800Nm of torque. Our test car had the £12,530 Performance Pack, which ups these figures to a headline-grabbing 556bhp and 900Nm of torque.

On the road, performance is sensational. Squeezing the throttle creates a wave of acceleration that continues until you’re forced to back off – or change up early using the tactile metal shift paddles.

The MCT dual-clutch transmission’s manual mode gives you plenty of control, although downshifts aren’t quite as razor- sharp as in the BMW. Plus, the gearbox kicks down a little too readily in automatic mode.

At the test track, the Mercedes sprinted from 0-60mph in only four seconds. The freedom to fully exploit the engine in an environment like this lets you appreciate its thunderous exhaust note at full volume.

While both rivals have the performance to run the Mercedes close in a drag race, what sets the SL63 apart is its ability in corners. The AMG sports suspension includes Active Body Control system, which virtually eliminates roll. They help the car feel lighter on its feet and change direction with a lot less fuss than the heavier BMW.

The SL’s direct steering delivers a more positive turn-in and it feels surprisingly agile for a car of this size. There’s lots of grip, and on bumpy country roads the SL doesn’t rely on its traction control as much as its rivals do. At the track, turning off the electronic systems allows you to enjoy dramatic, yet controllable, slides. But for all this muscle-car attitude, the SL63 rides well with its adaptive dampers in Comfort mode: only expansion joints and big potholes upset its composure.

All the cars in this test have eye-watering price tags, but the SL is the most expensive of the lot. Still, its breadth of ability, high quality and classy image mean that, for those lucky enough to be able to afford cars like these, it could be a price worth paying.