Mercedes AMG SL review

The Mercedes AMG SL is a car that can multitask – combining luxury with agility. It's the firm’s flagship convertible and a mainstay of the German brand’s range.

SL stands for ‘super lightweight' (a reference to the first-generation SL’s racing credentials), but this seventh-generation model is a well-equipped roadster that weighs almost two tonnes. Fortunately, Mercedes hasn't let that make much of a dent in performance. This is still a quick car.

Indeed, this is the first Mercedes SL to be developed by the car maker's high-performance subsidiary, AMG, and it gets plenty of tech to help it deliver a rewarding driver experience.

We’re talking about all-new aluminium underpinnings (to reduce weight), four-wheel drive (to improve traction) and four-wheel steering (to improve agility). Even the folding metal roof fitted to the previous two generations of SL has been ditched, making way for a lighter fabric version.

Then there’s the engines. To keep up with the likes of the Aston Martin Vantage Roadster, the Porsche 911 Cabriolet and the BMW 8 Series Convertible, Mercedes gives you a choice of three, starting with the SL 43, a 2.0-litre turbocharged four-cylinder. There’s also a 4.0-litre V8 model, the SL 55, and an uprated version of that, the SL 63.

But is the Mercedes SL any good? That's what this review will tell you. And once you've picked your new car, we can help you find the best price on our New Car Buying pages.

The Mercedes SL has always been a fine luxury roadster with a mildly sporting bent, but this latest AMG-badged version has a stronger focus on driver entertainment than ever.

Even the entry-level SL 43's engine comes packed with power, with 376bhp courtesy of a 2.0-litre four-cylinder engine. Its sub-5.0 seconds 0-62mph time isn’t far behind the V8-wielding Jaguar F-Type, meaning it’s more than fast enough without the fuel bills of that rival or the rest of the SL range. 

The more powerful SL 55 and SL 63 both have a brawnier 4.0-litre V8, delivering their power through Mercedes' 4Matic+ four-wheel-drive system.

With 469bhp, the SL55 has an abundance of power and a theatrical soundtrack to match – at our private test track we clocked one sprinting from 0-60mph in just 3.7 seconds. It’s more difficult to make a case for the flagship SL 63, because while it produces 108bhp more the 55, it’s only a few tenths quicker to 60mph. 

The SL 43 comes with sports suspension as standard, while the SL 55 comes with adaptive dampers that can be softened or stiffened at the push of a button. The SL 63 gets an even more advanced hydraulically-linked damper system. 

We’ve spent a good number of miles in the SL 55 in a variety of environments and remain impressed with how it can thrill you one moment and pamper you the next. In Comfort mode, for example, it does a fantastic job at rounding off bits of raised ironwork around town. It's even more cosseting than the softly-sprung Lexus LC 500 Convertible at motorway speeds. 

When you find yourself on a country road, you can knock it into Sport Plus mode and it will do a convincing impression of a proper sports car. Body control over mid-corner bumps and around off-camber corners is exceptional, and there is very little body lean. Combined with quite an aggressive rear-wheel-steering system, it feels unbelievably nimble for a convertible of its size and weight. 

The fancy set-up equipped on the SL 63 helps to make things sportier still, firming up the ride with stiffer damping for even better body control without compromising comfort too much. Building even further on the added sportiness is a limited-slip differential – reserved solely for the 63 – allowing you to easily get the monstrous power onto the tarmac with confidence. 

If we had a complaint, it would be that it can take a while to dial into the steering’s quick but not particularly linear rate of response. The 911 Cabriolet has a more progressive rack and its four-wheel drive feels a touch more rear-biased, letting you play with the balance of the car on the exit of corners.

Gearshifts from the nine-speed automatic gearbox are seamlessly smooth, and while the response isn’t as instant as the PDK auto gearbox in the 911, it suits the character of the rest of the car.

In terms of refinement, the SL generates a little more road roar than the LC Convertible on account of its wider tyres, but it’s not intrusive. With the roof up, wind noise is well contained. In fact, even with the top down, occupants are well protected from buffeting, especially with the fold-out wind-breaker fitted behind the back seats.

Mercedes SL driving overview

Strengths Nimble handling; smooth gearbox; strong engines

Weaknesses Steering isn’t particularly progressive; Porsche 911 Cabriolet has sportier handling

The Mercedes SL has low-slung seats, and a tall dash, high window line and wide centre console that cocoon its occupants.

The electric seats and steering wheel offer plenty of adjustment, although visibility can be tricky. The long nose that drops out of view and small rear window mean you’ll be using the standard-fit parking sensors and 360-degree camera a lot.

The dashboard is neatly arranged, with a large 11.9in centre touchscreen as the main centrepiece, with very few buttons around it. That looks tidy, but the car's functions are not that easy to use or find.

The screen is within close reach and you can adjust the angle at the press of a button to make it easier to read, but it's not the quickest to respond to inputs. Opening and closing the car's convertible roof requires you to swipe and hold an icon – which is distracting when you're driving – rather than pushing a switch.

The four-spoke steering wheel looks relatively busy, with two rotary controls below it that adjust the vehicle’s functions, including the drive modes, spoiler and suspension settings, and stability control. The touch-sensitive spokes are fiddly to use, but having all those separate spokes does make them relatively easy to locate by touch.

Our main gripe about the SL's interior is that the quality is rather disappointing. It makes a good first impression – with ambient lighting and soft leather on most surfaces – but some of the plastics feel brittle, and the fit and finish on sections of trim is disappointing.

Our test car suffered from buzzes on the front door panel and around the back seats. If you want a luxury droptop with a beautifully screwed together interior, look at the Lexus LC 500 Convertible.

Mercedes SL interior overview

Strengths Great driving position; easy to reach and see infotainment system

Weaknesses Visibility isn’t great; fiddly touch-sensitive steering wheel buttons; disappointing interior quality

There’s plenty of space for two six-foot occupants in the front of the Mercedes SL, with more than enough head, leg and elbow room.

It won’t take more than a glance at the two rear seats to realise that squeezing in four adults is ambitious, though. Those sitting up front will have to compromise their own legroom to free up a morsel of space in the rear footwell, and if the roof is up, head room in the back is limited. In fairness, this is the same with most sporty 2+2 convertibles. 

Nevertheless, if you need to take your children to nursery, or perhaps want to run your friends down to the local pub, the back seats come in handy for very short distances. You can also use them for a bit of extra storage room. 

It takes the roof 15 seconds to fold away and can be done up to 37mph. Handily, the roof stows away in its own compartment behind the seats, so it doesn’t intrude on the 213 litre boot. That's not as generous as the BMW 8 Series Convertible boot but comfortably beats the Lexus LC 500 Convertible. The Porsche 911 Cabriolet, meanwhile, has a boot and a frunk which offer more combined space.

In more relatable terms, the SL has enough space for three carry-on suitcases (versus two in the LC 500), but as with most convertibles you’ll have to heave them over a high load lip to get them in. All SLs come with a powered boot-lid.

When it comes to other storage, there’s a useful lidded cubby area that acts as a central armrest up front, and a lidded cubby by the centre touchscreen that has two small cupholders and a wireless charging tray tucked away inside.

The glovebox is just big enough to store a book and the door cubbies are narrow, but it's still a car you could quite happily take on a long-distance driving holiday for two without too much fuss.

Mercedes SL practicality overview

Strengths Lots of front space; decent-sized boot  

Weaknesses Limited rear space

With a significantly higher price tag than the previous generation version, the Mercedes SL costs way more than the BMW 8 Series convertible, slightly more than the Porsche 911 Cabriolet and around the same as the Lexus LC 500 Convertible. 

Even the cheapest version, the SL 43, comes with a six-figure price tag, which is a lot for something with a 2.0-litre petrol engine. The near-£150k SL 55 costs far more than a top-spec Porsche Carrera 4 GTS, while the most expensive SL 63 is treading on the toes of the sumptuous Bentley Continental GT Convertible.

All versions of the SL emit more than 200g/km of CO2, meaning they sit in the top company car tax bracket. The smaller engined SL 43 might seem like a good choice for fuel economy, but that’s not saying much when the official figure is around 30mpg. Mind you, that’s still a useful chunk more than the high teens you’ll see with the V8-engined SL 55 and SL 63.

All models sit in the highest insurance group, but better predicted resale values after three years than both the 8 Series Convertible and LC 500 Convertible help to soften the blow. If you’re planning on selling after three years, the 911 Cabriolet is a strong contender because it holds its value better than rivals. 

Fortunately, you shouldn’t need to add many options. All SLs come with ambient lighting, an air scarf heater integrated into the headrest, heated front seats and steering wheel, a Burmester sound system, sat-nav, adaptive LED headlights and dual-zone climate control.

While the warranty period is only three years, there’s no mileage limit. That’s handy, because Mercedes finished in 24th position out of the 32 manufacturers in our 2023 What Car? Reliability Survey. That’s above Jaguar (29th) but below Porsche (20th) and way below Lexus, which claimed top spot. 

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Mercedes SL costs overview

Strengths Plenty of standard equipment; slow depreciation

Weaknesses So-so warranty; hefty price tag