Mercedes-Benz SL 400 review
New looks, new tech, new transmissions - the Mercedes SL sharpens up its act.
Matt Robinson
Matt Robinson

Published on February 27, 2016

A striking facelift, a bit more power for the entry-point 400 and the addition of a Curve Tilting Function make sure the sixth-generation of the Mercedes-Benz SL - which, as a roadster, is nearing its 60th birthday - moves back to the top of its game. This 3.0-litre twin-turbo petrol engine might be the least expensive of the line-up but it remains a thoroughly premium product... and a damn fine machine to drive.

In the metal

The biggest work for the facelifted version of the 'R231' sixth-generation Mercedes-Benz SL has taken place at the nose. The lights, grille, bonnet and bumper have all been extensively reworked and the resulting car is eye-catching and attractive. Two 'powerdomes' adorn the bonnet, which still wears its distinctive vents up near the base of the windscreen, while the front lamps clearly evoke the Mercedes-AMG GT. Down below, the 'A-wing' air dam gives the SL real purpose and a link to the more powerful, AMG-tuned versions that top out its range.

Perhaps the most evocative upgrade is that diamond grille, as - with its wider lower portion - it is designed to hark back to the original SL Coupés of 1952 that swept to glory in the often-lethal Carrera Panamericana road race in Mexico. That's a nice little touch and the changes make it easy to spot compared to the pre-facelift model. Further amendments include the ability to drop the Vario-Roof on the move at speeds of up to 40km/h, a neat automatic boot separator that moves the folded roof out of the way to make accessing luggage easier and a new exterior colour by the name of Brilliant Blue. There's extra connectivity kit and trim finishes inside too, although all you really need to know here is that the SL's cabin is a glorious, wonderfully executed affair that feels worth the robust entry fee.

Driving it

Primarily an open-topped long-distance GT, the SL has always trod a fine line between luxury cruising and sporty back-road driving. It's still not quite the sportiest of big open-tops but there are some excellent dynamic machines in the line-up - this 400 model being one of the most impressive. It's the only SL that has gained power during the mid-life facelift, Mercedes adding 35hp and 20Nm to the biturbo V6 petrol engine, to leave us standing at 367hp and 500Nm; this is the engine that will power the forthcoming Mercedes-AMG C 43, incidentally.

And it's a proper zinger. Free-revving and with a lovely, clean and crisp bark when it's performing hard, it has more than enough clout to turn the 1,735kg SL 400 into a properly quick car. Four variants of the SL are available, including the V8-engined SL 500 with 455hp, and two AMGs with either 585- or 630hp. Yet the 400 is just nine tenths of a second slower than that ultimate AMG, the SL 65, to 100km/h, and unless AMG buyers opt for the Driver's Package - which raises the speed limiter to 300km/h, instead of the regulation 250km/h - then it's just as quick flat out too. More meaningfully, on the road the 400 feels ever so urgent in the midrange, making it all the premium roadster you could ever want or need.

It's helped by impressive steering, a superb balance between ride and handling (more on that in a moment) and decent brakes, although one strop over a SoCal mountain had them smoking after the final, manic descent. That jack-of-all-trades character in the body control department is because, while all SLs get 'semi-active' adaptive dampers as standard, buyers can opt for Active Body Control (ABC) with Curve Tilt Function. This adds an oil reservoir above each spring and a parallel damper, to ensure the car isn't just reacting to the road surface but feels like it's pre-sensing it. The system limits pitch, dive and roll magnificently, making the SL reasonably nimble for such a big machine, allowing you to explore the edges of its adhesion to devastating effect. Curve Tilt Function, by the way, is the new addition, making its debut here following its use on the S-Class Coupé, but it really works its best on a high-speed German Autobahn, rather than a twisting road.

The new 9G-Tronic nine-speed auto that replaces the old seven-speed unit is an odd one, though. It's perfectly smooth in its shift patterns and reasonably quick to respond to hefty boots of the throttle or clicks of the paddles... but on that last score, it won't always do what you want. Such is the torque of the 400 that it refuses to shift down to third or second when you think it might be useful, while on occasion it can grab for the next ratio up the gearbox just as you click the up paddle, meaning you sometimes slip through two gears and end up lower in the rev range than intended. However, some of that is forgetting that, with nine gears, it will be often in a higher ratio than you think it should be and it reacts best when just left in automatic mode, where it works well with the Drive Select parameters to offer a polished performance.

Of course, the SL remains a supreme cruiser. It's ultra-refined roof up or down, and if you are open to the elements, buffeting is kept well in check by the automatic wind diffuser that pops out of the rear bulkhead. The ride is simply divine, cosseting occupants from large, high-speed compressions and rippled inner-city surfaces alike, while the V6 and its attendant naughty exhaust (it can pop and burble on the overrun, although not as loudly as its V8 and V12 brethren) die away to near silence on minimal throttle openings. With a 65-litre tank and a combined economy figure of 36.7mpg, theoretically the range is in excess of 800km, but start driving it like, er... we did, and that will tumble quite dramatically.

What you get for your money

Prices for the SL 400 start at €163,000 in Ireland, so it's not cheap by any definition. However, new equipment in the SL amounts to Apple CarPlay, an LED Intelligent Light System with Adaptive High-beam, Parking Pilot, Comand Online, Dynamic Select, Magic Vision Control, Attention Assist and Active Brake Assist, so it's a well-equipped luxury motor that makes its driver feel rewarded for choosing it.


BMW 640i Convertible: more of a GT than a sports car and not a two-seater like the SL, the 640i costs €111,450 and doesn't have the Merc's sense of occasion.

Jaguar F-Type V6 S Convertible: €120,000 gets you in the V6 S Jaguar, the Mercedes' closest two-seat roadster rival. This is sportier than the SL, but less practical.

Porsche 911 Cabriolet: unlike the SL again but as close as you'll get from Porsche, especially now all models are turbocharged. Not as relaxing as the Benz ever though.


Never has the phrase 'entry-level' been more inappropriate than with the new Mercedes SL 400. It's arguably the pick of the roadster range, because it's more than quick enough for anyone's road needs and yet it's cheaper to buy and run than any of its stablemates by a considerable margin. It's also one of the best-handling versions of the SL, thanks to its relatively low weight and the lack of mass over the nose, and it proves to be a hugely enjoyable machine that is extremely relaxing to just cruise along in. If you've always wanted a Mercedes SL, then this is a fine example of the breed.