Mercedes-Benz SL (2012 – 2020) Review

This generation of Mercedes SL roadster values comfort over outright handling ability, which will suit some drivers and put others off. It’s engaging to drive, though, and makes a good case for itself against the likes of the Jaguar XK and its British rival, the Bentley GTC, but a BMW 6 Series Convertible is a more nimble (if less exclusive) drop-top. Only a Porsche 911 Cabriolet has the full measure of it. Read on for our full Mercedes SL review.

The archetypal grand tourer, the Mercedes SL boasts a pedigree that few grand tourers can match.

The first was launched in the 1950s in its maker’s pursuit of Le Mans glory, and since then the Mercedes SL has matured into one of the best two-seater sports cars money can buy, with an opulent interior and powerful range of engines.

This sixth-generation Mercedes SL convertible was launched in 2012 and built almost entirely of lightweight aluminium – a first for a volume production Mercedes – which means the car is 25 per cent lighter than its all-steel predecessor, and more rigid.

There were also significant weight reductions with the folding roof, seats, suspension and running gear.

The interior of the Mercedes SL is a lavish affair, with deep leather seats, soft-touch materials and brushed aluminium trim. Both the driver and passenger get acres of space and it’s ideal for long trips, with plenty of room.

Admittedly, things get a little blustery with the roof down, but the optional wind deflector improves matters no end. The retractable roof is also easy to use, folding away neatly into the boot at a press of a button, leaving a respectable 364 litres of storage.

The engine line-up consists of five options, including two AMG models, ranging from 306PS to 630PS. The 0-62mph sprint can be covered in as little as 4.3 seconds by the V8 bi-turbo, while the naturally aspirated V6 will achieve it in 5.9 seconds.

The SL350 with the naturally aspirated V6 was phased out in April 2014 and replaced with the SL400, which uses a V6 bi-turbo that brought an increase of 27PS.

All of the engines are mated to a seven-speed automatic, with four driving modes, which span from comfort to full-on throttle-blipping racing. However, regardless of which mode you choose, the Mercedes SL is always sure-footed and predictable in its handling.

Admittedly, the car feels more comfortable as a cruiser, but it will still answer a need for speed for any keen used car buyers. Only the AMG versions can rival the Porsche 911 or Maserati GranTurismo for outright acceleration.

Fancy a second opinion? Read heycar’s Mercedes SL review here.

The aluminium body brought improvements to the Mercedes SL’s handling, but there is no hiding the sheer size of the car.

Push the AMG versions hard and you’ll fight and wrestle with them as the rear wheels try to snap sideways.

The Mercedes SL also struggles in tight bends, with numb steering making it difficult to identify which wheels have grip and which ones don’t. 

Both of the AMG engines are linked to a Speedshift Plus 7G-Tronic automatic, which can be driven in a ‘Controlled Efficiency’ or ‘sport’ mode.

There’s also the option of driving in manual, via paddles behind the steering wheel. In practice, all the options work well, with instant gearshifts and decent spacing between the ratios.

We particularly liked the ‘Controlled Efficiency’ option for wet roads, as it changes up through the ratios smartly to avoid hard acceleration.

As well as bigger powerplants, the Mercedes SL AMG models get sports suspension and 19-inch wheels, plus a number of buttons and switches that enable drivers to tweak settings for the powertrain and suspension. 

If truth be told, the V6s in the SL350 and SL400 are more than enough for daily use, and we struggle to fathom why anyone would venture beyond the SL500 for high performance.

For sure, the AMGs are fun, but the Mercedes SL feels more comfortable with less power, and this makes it a much more enjoyable car to drive.

The Mercedes SL is available with five engines, with power outputs ranging from a sedate 306PS to supercar-rivalling 630PS.

For most drivers the SL350 and its naturally aspirated V6 will be more than enough, with 306PS and 370Nm of torque. Put the Mercedes SL to task, and the V6 will gallop from 0-62mph in 5.9 seconds and reach a top speed of 155mph. 

However, there is a fly in the ointment: the SL350 and its V6 was phased out in April 2014, and replaced with the SL400, which uses a V6 bi-turbo with a power increase of 27PS.

The V6 bi-turbo used a touch more fuel, but improved performance, with a 0-62mph time of 5.2 seconds. 

If power is your thing, then the V8-powered SL500 will be the car for you, with its 4.7-litre engine thumping along with 435PS and 700Nm of torque. Not only is the V8 silky smooth, it makes a wonderful noise.

As with the SL350 and SL400, the V8 is coupled to a 7G-Tronic Plus seven-speed automatic that allows the ‘box to be driven in manual or full auto modes.

The brand’s auto options can sometimes be hit-and-miss, but the 7G works well in the Mercedes SL and provides smooth changes with plenty of running room between fourth and fifth gears.

If you want a truly brutal supercar experience, then Mercedes also offered two AMG models.

The SL63 AMG uses the same V8 as the SL500, but it has two turbochargers to produce 537PS and 800Nm of torque.

If that’s still not enough, then the range-topping V12 SL65 AMG has 630PS and 1000Nm of torque. Both of these engines return a raw supercar experience, with a burbling soundtrack and a rapid turn of pace.

In fact, with the roof down, there are few racing engines that can match the pure joy of the AMG units, with a top speed of 155mph (electronically restricted) and a 0-62mph time of less than 4.5 seconds.

But, be warned: with so much power on tap, the Mercedes SL becomes more than a tad skittish on damp or challenging surfaces, and can be a real handful to keep in check.

Euro NCAP did not crash test the Mercedes SL, but given the record of the company and the number of safety systems fitted as standard, you can be pretty confident about the protection it offers in a crash.

The Mercedes has an active bonnet, which pops up in a collision with a pedestrian to protect their head from hitting the engine below.

Active brake assist, however, should hopefully avoid that in the first place, by automatically slowing the car if an obstacle ahead is detected.

Front and side airbags are standard, and there’s also a driver-monitoring attention assist system. Mercedes even included a standard first aid kit and warning triangle.

The Neck Pro active head restraints push forward by 40mm and upwards by 30mm, supporting the head and reducing the risk of whiplash.

There’s a rollover protection system, while Pre-Safe will tension the seatbelts during emergency manoeuvres, again to stop passengers from moving around.

Another clever feature is ESP Curve Dynamic Assist, which helps cut understeer – running wide – when accelerating through bends via subtle use of individual wheel braking.

It also contributes to the stable and confident feeling you get when cornering.

There were no towing capacities quoted for the Mercedes SL, so don’t be thinking you’ll be hauling a caravan on holiday in fine style.

As you’d expect from an upmarket grand tourer, the interior of the Mercedes SL is a luxurious and opulent affair, with copious amounts of leather and aluminium trim.

The two-seater layout ensures that both the driver and passenger get plenty of legroom and headroom, while the heated leather sports seats mean that long trips can be covered in complete comfort.

Admittedly, things get a little blustery with the roof down and this can make it a little uncomfortable, but the optional wind deflector solves this problem. The retractable roof is easy to use, folding away neatly into the boot at a press of a button, which makes it perfectly suitable for the British weather.

With the roof up, the Mercedes SL feels like any other fixed-roof GT car, with little in the way of road noise or engine noise.

Obviously, if you push it hard, the engine becomes noticeably loud, but this is to be expected from any car with potent powerplants. If you specify one of the AMG engines, then be prepared for a thunderous engine note, which will rumble through the cabin like a small earthquake.

For the driver, the cabin layout is faultless, with a workmanlike simplicity that makes it a pleasure to use. The driving position is comfortable and adjustable, via three buttons located on the door, while the view of the road – and all four corners of the car – is clear and unobstructed.

The boot capacity for all Mercedes SL models is 504 litres, which is reduced to 364 litres with the roof down. The car is also supplied with a useful boot cover that makes it impossible for you to squash anything in when the roof folds down. However, when the roof is retracted, it is rather difficult to fit larger objects into the boot, so it’s always an idea to load up before lowering the roof. 

As you’d expect, the AMG models get the usual scattering of racing logos and lettering, along with carbon fibre trim and uprated leather seats. The door sill panels also get chrome illuminations, neck-level heating and ambient lighting.

However, no matter what trim you choose, the Mercedes SL is always comfortable and spacious. 

The Mercedes SL is a very well finished car. The company may well have made it in lower volumes than its mainstream models, but you sense that it also lets only its most experienced technicians work on the car at the factory.

Like building a Rolls-Royce, making a Mercedes SL is a career goal you strive towards.

Certainly, it’s impeccably finished outside, with arrow-straight lines and deep paint quality. Inside, it feels gorgeous, with the materials you touch most often seemingly notched up a grade or two compared with normal Mercedes cars.

The leather seats feel wonderful and nudging the gear lever back and forth is deeply satisfying.

However, one or two of the buttons give the game away that this is an older design of Mercedes, as you can spot some from lesser models in the company’s line-up, which undermines the bespoke nature a little.

The dashboard of the Mercedes SL is well laid out and intelligent in its design. The facia is dominated by a large seven-inch display, which clearly shows the sat-nav and infotainment system.

The large screen is flanked by aluminium air vents, which add an extra dash of style along with the leather- stitched trim.

All of the buttons and interior controls are large and easy to find. We particularly like the heating controls, which are operated by rotary dials that have a satisfying ‘click’ when rotated.

Entry price to used Mercedes SL ownership starts at £18,000 for a well looked after SL350 that’s 11 years old and has covered around 75,000 miles.

If you want the more potent SL500 with its V8 engine, you will need to up the spend to around £24,000 for a car of similar age and mileage.

Choose a newer model, and a six-year-old SL500 with 30,000 miles will cost about £37,000, while an SL400 will be in the ballpark of £33,000.

Look to the AMG models and an SL63 will cost from £32,000 for a 10-year-old car with 50,000 miles under its wheels.

A six-year-old version with 30,000 miles will be around £52,000, while the outrageous SL65 with its V12 engine will cost from £85,000, if you can find one for sale.

The AMG models have a lusty thirst for fuel, so reckon on 18mpg even if the official figure was claimed at up to 28.8mpg.

With the more widely available SL350 and SL400 models, you’re looking at real-world economy in the low-30s, which isn’t far off the official claims. The SL500’s daily 26mpg is about bang-on what Mercedes claimed when it was new.

Road tax for the AMG models will cost £710 and £735 for the SL63 and SL65 respectively, which is a hefty burden to shoulder every 12 months.

For the SL350 and SL400, you’ll pay £305 and £335 respectively, while the SL500 comes in at £415 per annum to be on a par with most rivals.

Most Mercedes SL owners will stick with an official dealer for servicing, which won’t be cheap, but will help with the car’s residual value when selling. However, don’t dismiss a good independent specialist to help save some cash.

Unfortunately, insurance is never going to be cheap for a Mercedes SL, with the range sitting in groups 48 to 50 (out of 50).

The company didn’t offer trims, but it did differentiate between engine options, so the Mercedes SL350, Mercedes SL400 and Mercedes SL500 have a seven-speed automatic transmission with cruise control, steering wheel gearshift paddles and ‘S’ mode featuring modified shift points, climate control and a panoramic glass vario-roof with blind.

There’s also a multi-function sports steering wheel with flattened bottom section, metallic paint, ESP, first-aid kit and warning triangle, Bluetooth, ECO start/stop function, AMG body styling with front and rear aprons, side skirts, bi-xenon headlamps, LED daytime running lights and Parktronic with active park assist.

On the Mercedes SL63 AMG, you get 19-inch five-twin-spoke alloy wheels, sports suspension – based on the active body control active suspension system which is adjustable in two stages – an AMG radiator grille and AMG sports exhaust system,

Add to that ‘V8 BITURBO’ lettering on the front wings, Sports seats with AMG-specific seat upholstery and an embossed AMG emblem in backrests, wind deflector, speed-sensitive sports steering and brake calipers painted in grey.

Mercedes SL65 AMG customers enjoy Airscarf neck-level heating, keyless go, remote boot closing and hands-free access, plus a closing aid for doors. There’s a Mercedes SL 65 AMG-specific front apron and rear apron too.

It also comes with a Bang & Olufsen BeoSound surround sound system, AMG ‘V12 BITURBO’ lettering on the front wings and an AMG rear axle limited-slip differential.