Mercedes SL review

Our Rating: 
2016 model
By Auto Express Test TeamComments

The Mercedes SL is a status symbol and the latest model has the usual blend of style and performance

Acceleration, high-quality finish, electronic driving aids
Price, unremarkable looks, poor efficiency

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Few cars at any price can match the breadth of talents you get in a Mercedes SL. The elegant roadster comes close to supercar levels of straight-line speed matched with the superb refinement and safety technology you’d expect from a luxury saloon. 

It treads the line between being a full-fat sports car and luxury GT cruiser but is able to play both parts convincingly. The SL perhaps doesn't have the drama of a Jaguar F-Type Convertible but it sounds great, looks good and is rather practical considering its purpose.

The entry-level Mercedes SL 400 could even be the pick of the range, but if your budget can stretch the Mercedes-AMG SL 63 is definitely worth a look.

Our Choice: 
Mercedes-Benz SL 400

The Mercedes-Benz SL has been around for over 60 years in one form or another. This latest version plays to its traditional strengths by offering wind-in-the-hair thrills in a super-stylish package.

There’s often some snootiness from sports car enthusiasts where the Mercedes SL is concerned. The big Mercedes roadster is typically evaluated against more athletic rivals like the Porsche 911 Cabriolet and Jaguar F-Type, company that can make it seem a bit of a softy - especially in guises unfettled by Merc’s AMG performance arm. The likes of Maserati’s GranCabrio and the Bentley Continental GT will also be mentioned in the same breath but the BMW 6-Series Convertible is close to the non-AMG cars in terms of price.

Ultimately the character of the car varies significantly depending on your picks from the wide choice of suspension and engine options. At the top of the range, the Mercedes-AMG derivatives have the pace to challenge supercars whereas the more affordable SLs revel in an easy-going character that’s far closer to Mercedes’ big 4-seat convertibles, the S and E-Class Cabriolets.

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The latest 6th generation version of the SL launched in 2012 and has a lightweight all-aluminium bodyshell in a bid to better live up to its ‘Super Light’ name. A 2015 facelift upped its performance game further with a new 9G-Tronic nine-speed gearbox, Dynamic Select driving modes and Active Body Control.

The SL's understated looks belie its impressive performance figures, while handling and fuel economy are also much improved on the latest car. A retractable hard-top roof adds a lot of extra noise reduction compared to the soft-top BMW and Jaguar F-Type while its fast operating time is ideal to help avoid those summer showers.

All engines on offer are twin-turbocharged. The line-up ranges from a V6 up to a V12 with power outputs starting at 362bhp in the SL 400 and rising to a monstrous 622bhp in the mighty Mercedes-AMG SL 65. Predictably, the price rises too with the SL flagship hitting the £172,000 mark, taking it deep inside supercar territory. 

Engines, performance and drive

The SL sits between being a full-fat sports car and luxury tourer but performance is still impressive

The large V8 petrol engine in the SL 500 is blisteringly quick, accelerating from 0-62mph in 4.3 seconds and up to an electronically limited top speed of 155mph. Opt for the Mercedes-AMG tweaked SL 63 or SL 65 models and acceleration reaches supercar levels, although the handling is still more suited to cruising than lapping a race track.

A naturally aspirated SL 350 was offered in the range until mid-2014, when a twin-turbocharged SL 400 model replaced it. This new entry-level option has 362bhp and costs exactly the same. It's a definite improvement over the 350, offering the kind of effortless performance you expect from an SL despite the 6-cylinder powertrain.

The driving position is very comfortable and offers plenty of adjustment. Visibility is also surprisingly good whether the roof is up or down, however the electronically controlled wind deflector can obstruct the rear view when raised.

The car is much lighter than before and features a 57mm increase in track. This really improves handling, and although the SL can’t quite match a Porsche 911, it isn’t a million miles off.

The Mercedes Dynamic Select lets you pick from a menu of Comfort, Sport, Sport+, Individual, and Eco modes. But there’s also an optional Curve control system which lets the active dampers tilt the car fractionally in corners to improve ride comfort.

In Comfort setting the SL is more refined and comfortable than a roadster has any right to be. Even with the roof down, engine and tyre noise is extremely well supressed. Select Sport mode and everything becomes more immediate. The V8 rumble is an ever present while steering weight increases and the responses of the throttle and gearbox sharpen. Sport+ is another level with more leeway in the stability control system as the SL powers out of corners but the ride becomes harsh on all but the smoothest surfaces.  

Even in its sportiest setting the SL doesn’t change direction with the nimbleness of a Porsche 911 or F-Type. There’s always the feeling that you’re leaning on the electronic trickery rather than the talents of the chassis but the end result is undeniably impressive.  


In terms of on paper performance there isn’t a huge amount to choose between the four twin-turbo Mercedes SL engines. The SL 400 will get to 62mph in 4.9s, then it’s 4.3s for the SL 500, 4.1s for the Mercedes-AMG SL 63 and 4.0s for the V12 SL 65. All are limited to 155mph.

The justification for the sizable price steps that take you from £73,000 for the SL 400 to the £173,000 SL 65 lies in the power and torque on offer. Where the SL 400 has 362bhp and 500Nm, the V8 SL 500 has 449bhp and 700Nm. Beyond that, the Mercedes-AMG magic touch gives the SL 63 577bhp and 900Nm while the SL 65 gets 621bhp and a nice round 1,000Nm.

You’re paying for the massive extra flexibility these power and torque increments offer and the potential to hit top speeds on the far side of the 180mph barrier when the speed limiter is disengaged and track conditions allow. Plenty of SL buyers will see that as money well spent. 

MPG, CO2 and running costs

Running costs will be steep, although the SL 400 is the most efficient SL ever built

There’s no hiding from the fact that the Mercedes SL is an expensive buy, and this statement even holds up in light of its costly rivals. When you look at its fuel consumption, it’s enough to make a Toyota Prius driver faint.

In its most efficient set-up, with a 3.0-litre twin-turbo V6 petrol engine, it barely returns 37mpg, however this is a massive 30 per cent improvement on the previous model. The SL 500 manages 31mpg on the combined cycle but we only achieved 24mpg on our 350-mile test drive. At the top of the range, the official figures for the SL 65 are 23.7mpg and 279g/km.

In short, running costs can be expected to be high and tax bills will also sting. However, it's no more expensive than a BMW 6 Series and buyers in this market will be prepared for some hefty bills.

Insurance groups

Unsurprisingly, the SL sits in insurance group 50 because of its price and performance. Again though, if you're buying a car in this sector of the market, that's to be expected.

Interior, design and technology

Cabin is lacking the opulence of the S-Class Cabriolet but it's still a very pleasant place to sit

The sixth-generation Mercedes SL has quite a bit to live up to. Over the years the SL design has been evolved rather than reinvented, and the body has been smoothed out compared to the previous model, which highlights a desire to stay true to the original. A long bonnet and small cabin cries out traditional roadster and it looks far more menacing than it did before the latest facelift. 

There’s a far more aggressive front end on the latest car with more defined front and rear bumpers along with new alloy wheel designs. The Mercedes-AMG models also feature unique 'Bi-turbo' badges on the flanks. 

In the cabin, the Stuttgart manufacturer lives up to its heritage, by tastefully blending fine leather, metal trim and aero-inspired instruments to create a feeling of grandeur. 

Sat-nav, stereo and infotainment

As the new SL was just a facelift Merc hasn't fitted the mouse-like controller for the Command Online infotainment system, instead sticking with the old swivel wheel. It's still easy enough to use and quite responsive. There’s also Apple CarPlay integration and a mind-boggling array of other features.

The colour display is bright but the graphics do look a little dated compared to the new systems you find in BMW and Audi models. However, it is nicely integrated into the dash rather than perched on the top, so makes the cabin look a lot better packaged.    

Practicality, comfort and boot space

Only seating for two, but a big boot and nifty storage features make the most of the space on offer

When you think about the Mercedes SL, forget the need for four seats, non-mark materials and useful things like resistant plastic bumpers to squeeze into a parking slot.

The SL instead focuses on giving driver and passenger ample room inside the cabin, while the boot - which has 350 litres with the lid down - is more than big enough for a couple of small suitcases. Parking sensors are standard and to get the most out of the British summer, the hard roof comes off in 20 seconds.

As standard you get a driving position with a wide range of adjustment and seats that are shaped for comfort rather than vice-like side support. Our AMG Line model, however, added the £1,725 Active Multi-Contour Seat package with its active side bolsters that prop you up during hard cornering and a massage function with seven modes to help the miles fly by.

Leg room, head room & passenger space

The SL is more of a GT cruiser than a sports car, therefore, it has the classic long bonnet and cab-rearward design but it is a strict two-seater. With the roof in place there is a good amount of headroom for both passengers, with enough space for the tallest of adults to stretch out, too.   


For a two-seat roadster the SL is rather practical. With the roof in place the boot measures in at 500 litres, but even with it stowed there's still 350 litres of space. Loading items isn't an issue either as a tilt function lifts the roof by 25 degrees when it’s stowed in the boot to help you get your luggage in. 

Reliability and Safety

You can bank on an excellent safety rating such is the level of technology on offer and reliability should be good too

The Mercedes SL hasn’t been tested by Euro NCAP, but thanks to a large array of airbags and electronic safety features, as well as the German brand’s excellent reputation, potential buyers can be sure it will rate five stars for safety.

It's brimming with driver aids such as adaptive braking, stability control, anti-skid mechanisms and traction control, and it also includes a system that detects when the driver is feeling tired. Older versions of the SL developed a few electrical gremlins after a few years, but this new model seems to be holding up very well.

Mercedes finished just outside of the top 10 manufacturers in the 2016 Driver Power survey, finishing in 12th place after an 11th place finish in 2015. Although not the best position to be in, Mercedes will be pleased to hear it finished ahead of rivals BMW and Audi, but Jaguar was ahead in 6th place. 

Driver Power 2016 results


The Mercedes SL comes with a three-year/100,000-mile warranty that’s fairly standard in the industry. There’s also up to 30 years’ cover against corrosion and Mercedes-Benz Roadside Assistance which includes up to 30 years of breakdown cover across Europe.


Depending on the age or mileage of your SL, Mercedes will carry out an ‘A’ or a more comprehensive ‘B’ service. There’s also the option of Mercedes Service Care which splits servicing costs into manageable monthly payments but you wonder how many SL owners will need to take up that option. 

Last updated: 10 May, 2016