We like
Badass looks, strong turbo V6, clever boot/roof mechanism, fuel economy

Room for improvement
Hefty weight, dated interior, occasional clunky transmission

Price and equipment

IT IS hard to put a value on styling and looks but the SL400’s $217,715 pricetag includes perhaps the SL’s most defining feature – its unmissable looks and visceral road presence.

Just how much those looks are worth is up to the customer but the SL has the same big-bad-Merc convertible aesthetic that turns heads wherever you go, regardless of whether you have forked out $368,715 for the AMG SL63 or the most affordable version.

In addition to those stunning looks, each variant in the range also offers the joy of open-top motoring as well as the security and comfort of a coupe thanks to its folding solid panel roof, a 485-litre boot, rear-wheel drive, turbocharged petrol power and room for two.

For your cash, you get leather sports seats with heating and ventilation, an 11-speaker 600W Harman Kardon stereo and electro-hydraulic folding hard-top roof – but over its predecessor adds a new Comand Online media system with Apple CarPlay connectivity, an LED Intelligent Light System and 19-inch wheels – an inch bigger than the previous car.

Its V6 engine might not have been hand-built in Affalterbach but the entry SL does get some AMG influences in its updated bodywork and some sportier bodykit.

As if the aesthetic refresh and a dusting of extra kit wasn’t enough, the SL400 also got a price chop of $9610 with a mid-life update in late-2016.

Interior

While the SL400 interior has undergone a few updates with the facelift, you can still tell its is largely based on a car that has been around for more than six years.

It is still a pleasant place to be, is well screwed together and all materials are the quality you would expect from a high-end sportscar, but the sprawling layout of buttons and dashboard design appears to have evolved little, and still has elements of the generation before it.

The adoption of a smaller electronic gear selector, central digital drivers information screen and cross-design air vents has helped, and the cabin is still comfortable with an excellent seating position and space for both occupants.

One of the SL’s defining features for many years has been the folding hard-top, which offers fixed-roof car security and resistance to malicious damage as well as offering an excellent, cosy cabin when the roof is in place.

Operation is a little on the long side to allow for all the various clever stages of stowing the panels in the boot space but the novelty of the folding movement did not wear off.

There is also an ingenious function that partially lifts the roof mechanism out of the way when the roof is towed and boot access is required. The clever feature allows a much easier access to a surprisingly large luggage area, even with the top down.

With such a large roof to tuck away, cabin space is limited and there is a shortage of spots to put things even if humans are accommodated sufficiently.

Touches such as the Airscarf neck heaters, heated and cooled seats, and an electric rear wind break help make the cabin a comfortable place when the roof is down, encouraging maximum use of the SL’s classic open top.

Engine and transmission

For the most affordable and least potent version of any model range, the SL400 does very well with 270kW and 500Nm of torque, which is enough to accelerate its 1735kg heft from zero to 100km/h in just 4.9 seconds.

And it feels quick too with eager acceleration off the mark and when up and rolling, accompanied by a surprisingly satisfying exhaust note that does not belie its V6 origins but with a fine un-muffled sound.

While drivers can pick their own gear with steering wheel paddles, we left the excellent 9G-Tronic automatic transmission to its own devices for a majority of the time thanks to an intuitive operation.

Surprisingly, the auto did occasionally make a strange clunky shift as if it couldn’t quite decide whether to swap up or down the ratios but it was a rare occurrence.

There will be SL fans that consider anything other than the vicious 430kW/900Nm turbocharged V8 AMG SL63 flagship a soft option but we totally disagree. In isolation, the 400 has plenty of performance that would keep enthusiastic drivers happy all day. And the same applies even more so to the 400’s handling.

Ride and handling

If you want to pull 1-G in corners and worry Porsche 911s on the track then none of the SL range is really for you and we would recommend something from the AMG GT range instead.

The SL, whether it be powered by the range-topping twin-turbo V8 or a V6 is more concerned with elegance and muscle than shredding lap records.

That said, for a big heavy rear-drive, the SL400 has a surprisingly agile nature and we particularly like the sharp steering and responsive turn-in. It’s huge fun pointing the SL’s long snout through corners and feeling the whole car respond obediently to instructions.

While the SL is a big car and measures 4631mm long, the occupants are positioned closer to the rear axle for a true sportscar sensation when carving corners.

When a straighter road beckons under clear skies, the SL400 really comes into its own with the power to cruise comfortably and a ride that cossets occupants.

The 19-inch, five-spoke wheels that our test car rolled on completed the exterior with a minimalist but almost racecar look, but their low-profile tyres did a good job of insulating road noise and imperfections from the cabin.

A carefully tuned chassis is also credited with the supple ride when cruising but is a good balance for when the way ahead turns wiggly.

The SL400 is a strong all-round performer with the ability to reward enthusiastic drivers and passengers on long road trips alike, but our favourite times with the big Merc were when we found a busy suburban street, popped the roof, set the cruise control to 40km/h and enjoyed the envious glances.

Safety and servicing

Mercedes has built a reputation for offering vehicles with a high safety standard and the SL is no exception. Standard safety kit includes a class-leading selection of electronic safety systems. We particularly liked the driver fatigue monitoring which rates the driver from one to five on how alert the car senses them to be.

Other systems include Driving Assistance Plus which brings autonomous braking, adaptive cruise control, lane departure warning with assistance, blind spot monitoring and Pre-Safe that can mitigate the severity of a rear impact.

In the event of a collision, an active bonnet reduces harm to pedestrians, while a pop-up roll-over hoop protects occupants.

In addition to more conventional airbags for both occupants, head-protecting airbags are located in the doors to offer impact protection even when the roof is stowed, while side protection airbags are installed in the seat sides.

The SL400 requires a service every 25,000km or each year and the German car-maker offers owners a number of pre-paid servicing plans to take care of scheduled costs.

One option is a Silver capped-price plan, which fixes the price of a service for the first three visits, including brake-fluid change and cabin filter swap.

Upgrading to the Platinum plan covers wear-and-tear items such as front brake discs and pads.

Road Care is also extended to fourth and fifth-year Silver and Platinum packages.

Verdict

In the shadow of the mighty Mercedes-AMG SL63 we don’t think the SL400 range-opener can truly shine as brightly as it deserves, but if you haven’t been given a taste of blood by the $368,715 version then the most affordable SL is an incredibly strong performer for a lot less cash.

It has virtually the same looks as the two more expensive variants which, let’s be honest, is what most owners love most about the venerable SL – one evening your reviewer stood in their driveway simply looking at it for 20 minutes.

But it is not all show because the SL400 backs up its sportscar promises with impressive performance and lively handling.

Given the somewhat superfluous money-no-object argument, of course we would pick the fastest, most potent version with AMG badges, but in a real purse-string world, the SL400 is our pick of the Mercedes’ big sportscar range.

Rivals

BMW 6 Series Convertible from $195,500 before on-road costs
BMW’s big convertible also offers power from a 3.0-litre turbo six, rear-drive and big GT drop-top cruiser comfort but it can accommodate occupants in a second row of seating. The Mercedes’ clear advantage lies in its more secure folding hard top versus the BMW’s fabric roof.

Jaguar F-Type convertible from $138,425 before on-road costs
Jaguar’s two-seater convertible also offers 3.0-litre forced-induction V6 power and rear-drive fun but it lacks the boot space of the Merc and it doesn’t have the folding hard-top for especially cold winter days or parking in questionable suburbs.

Porsche 911 Cabriolet from $239,000 before on-road costs
Porsche offers another 3.0-litre turbo six option in the convertible rear-drive segment but its rear-mid-mounted flat six offers a more dynamically rewarding option than the SL. Porsche fans can equal the Mercedes hard-top convertible fun proposition by upgrading to the Targa for $255,100 which brings a clever sliding roof mechanism and four-wheel drive.