Mercedes-Benz SL Class Convertible Review


As Mercedes’ flagship two-seat convertible, the SL isn’t short of glamour or opulence. The long bonnet in front of the snug cabin gives the car a very racy, sports car-like appearance (although, as we’ll see, this is a little deceptive), while the short rear overhang also contributes to the overall effect. When in place, the low-slung roofline does the raciness no harm, either, and when you retract the metal hood, the car looks even better. It won’t quite grab the attention that say, a Jaguar F-type or Maserati Gran Cabrio would get, but not far off. All versions of the car look as desirable as they should at this price, but the sportier AMG versions get meatier body styling, fruiter exhausts, and a few more badges and spoilers to let all and sundry know how big your engine is.


Standard electric adjustment for all aspects of the driving position make it a doddle to get comfy

The SL’s cabin is exactly what you expect from a luxury convertible; a collection of lush materials and high-tech gadgetry, all fused together to deliver a comfortable and luxurious driving environment. The steering wheel is a little bit small, and it’s less hi-tech in here than the latest E-Class, something you notice looking at the main display screen, but it’s still pretty plush. Most of the controls are easy to use, and although Merc’s infotainment interface isn’t the most intuitive, it doesn’t take long before most of it becomes familiar. It has Apple Carplay, too, meaning a greater level of integration between your car and your iPhone. Standard electric adjustment for all aspects of the driving position make it a doddle to get comfy, while your all-round visibility is also pretty clear for a car of this type, even roof up.


Not an area of critical importance for most convertibles, so it’s no surprise that the SL does a reasonable-if-not-spectacular job on practicality. The two-seat cabin isn’t short of space for adult occupants, and there’s a decent amount of storage for odds and ends, with bins down behind the rear seats, lots of cupholders and a deep central cubby that’s lockable too. The boot has enough capacity for a couple’s holiday luggage, but not much else. The roof raises and lowers in 18 seconds, and you can operate the mechanism at speeds of up to 25mph, which could be very helpful if you get caught out by a sudden downpour. Rivals with cloth roofs do open a bit quicker, but the ballet of watching the SL’s metal hard top, and the added security it provides, is difficult to argue with.

Ride and handling

The 400 and 500 versions of the SL come with an adaptive suspension that changes its behaviour according to which of the driving modes you select; but, regardless of the setting, it’s much better at playing the role of luxury cruiser than that of the sports car. The smooth ride and impressive refinement make it perfect for destroying long distances in a relaxed and easy manner, and while the size, weight and slightly numb steering prevent it from dazzling you in the corners, it still handles very capably, with strong body control and reasonable grip. We say reasonable because, well, with all the weight at the front and a powerful engine, if you get greedy with the throttle, the rear tyres will start sliding, even in the dry. You can also specify an optional set-up with systems called Active Body Control and Curve Tilt Function. The former anticipates impending body movements when stopping, going and cornering, and counteracts them before they’ve even started, while the latter makes the car lean into a bend by a couple of degrees, like you would do if you were on a bicycle. The Active Body Control system comes as standard on the SL 63, and while it makes the 63 feel nimbler and more aggressive, the car still does its best work as a (very) high-speed cruiser. The SL 65 has a version of the same suspension, but with harsher settings. However, we’re yet to try it.


Four petrol engines are available in the SL, a V6, two V8s and a V12. The entry-level V6 in the 400 is a twin-turbocharged 3.0-litre with 362bhp, and it’s a real peach. Ordinarily, your progress is smooth, brisk and effortless, helped even further by the slick action of the standard nine-speed automatic gearbox. When you need to go faster, though, it’ll oblige in impressive fashion. Plant your right foot, and the gearbox will drop down to the perfect ratio, and you’re propelled towards the horizon with serious force. We haven’t tried the SL 500 with its 449bhp V8, or the SL 65 with its monstrous 621bhp V12, but we have had a go in the 577bhp SL 63. Looking at the bald numbers, you might struggle to see the point of the 63; it has the same (limited) top speed as the 400 and it’s only 0.8sec quicker from 0-62mph. However, the sensation of pace it delivers is totally different. While the 400 is impressively fast, the 63 is truly explosive in the way it accelerates. Overtaking manoeuvres take little more than a flex of your ankle, and you’re halfway down the road before your victim even knows what’s happening. It sounds utterly mind-blowing, too.

Running costs

If you settle for the 400 model – which we suggest you do – your running costs won’t be too ruinous

Obviously, you don’t buy an SL if you live life on a shoestring, but compared with other luxury convertibles, the prices aren’t outrageously expensive. If you settle for the 400 model – which we suggest you do – your running costs won’t be too ruinous, either, with official fuel economy standing at a pretty reasonable 36.7mpg. If, however, you’re a buyer at the other end of the spectrum, the SL 65 will cost you a lot more – we’re talking six figures more – and you’ll do very well to get anywhere close to the claimed fuel figure of 23.7mpg. Don’t even ask about insurance costs, either, but the argument stands that if you can afford to even consider buying a 65, then you can probably afford to run it, too. It’ll depreciate less than a lot of luxury convertibles though, something worth considering, as this is often the biggest running cost with cars of this size and price. Similarly powerful Bentleys suffer far more.


Take a look at Warranty Direct’s Reliability Index, and you’ll see that Mercedes Benz figures a lot lower down in the manufacturer rankings than perhaps they ought to. Even worse, the SL is one of the brand’s worst-performing cars, with a pretty much rock-bottom score for mechanical dependability. Interestingly, almost half the faults reported are electrical, with the next largest area of concern being axle and suspension problems. Any issues that do arise will undoubtedly cost a packet to put right, which will be exactly why the SL is quite so far down the rankings – having said that, Mercedes durability is supposed to be improving, and while this version of the SL is only a facelift, it should hopefully have been imbued with a bit of the hard-wearing spirit of the latest S-, E- and C-Class.


The optional Driving Assistance Package adds extra clever aids like lane-keep assist and radar cruise control

All the usual stuff – six airbags and stability control, for instance – is included in the standard safety roster, as is a tyre pressure monitoring system and autonomous braking. However, you also get cleverer systems as standard, like an active bonnet that’ll automatically pop up a bit to lessen pedestrian injuries, and a system that detects fatigue in the driver and urges them to take a break. The optional Driving Assistance Package (standard on the 65) also adds extra clever aids like lane-keep assist, a blind spot indicator and radar cruise control. Use all of them together an the SL will literally drive itself through traffic jams, with no input required. It’s a taste of motoring in the future, but it also virtually invites you to pay less attention to the road and become a lazier driver, so use it wisely. No Euro NCAP crash tests results are available for the SL, and because it’s so low volume, we wouldn’t expect that to change any time soon – the same is true for most of its competitors too.


The 400 and 500 versions come in one trim level – AMG Line – that provides plenty of luxury equipment as standard. That includes 19-inch alloys, LED headlamps with active high beams, climate control, remote locking, heated leather seats, automatic lights and wipers and a parking assistant that’ll steer the car into the space for you. You also get an infotainment system that brings together sat-nav, DAB radio, Bluetooth telephony, Apple Carplay and eight very powerful speakers. Then again, at this money, that sort of thing is the very least you should expect. That’s why the 63 and 65 versions look a little stingy; they get bigger engines, cleverer suspension systems and slightly revised styling inside and out, but don’t get a whole lot in the way of extra luxury kit. Whatever version you go for, it’s possible to send the price of your car to even more stratospheric levels by simply ticking a few boxes on the extensive options list, but actually overall, the SL is generously equipped.

Why buy?

Few cars combine luxury, technology and effortless pace so effectively

Because you want a luxury convertible for cruising around town and schlepping long distances, rather than blowing your socks off with its dynamic ability in the bends. View the SL for what it is – a luxurious touring convertible and not a sports car – and you’ll absolutely love it. Comfortable to drive, lovely to sit in and, most importantly, glamorous to look at.