Key considerations
- Available for £105,000
- 6.2-litre petrol V8, 7-speed twin-clutch semi-auto
- Thunderous, bulletproof NA drivetrain
- Coupes more expensive than Roadsters
- A bit wide for British roads
OVERVIEW
As regular readers will have noted, Mercedes has just unveiled a new AMG GT Black Series. This 730hp beast is the spiritual successor to the SLS Black. Which makes us think - where are all the SLSs? When did you last see one on the road, or even hear anyone talking about them? Why is there such a big disconnect between their ability (which is huge) and their public profile (which is tiny)?
The SLS was AMG's first ground-up, clean-sheet car. Allowing AMG the latitude to do that was a massive step for Mercedes, given their long but very cautious association with the Affalterbach crew. How long? Well, AMG had been an official M-B tuning department since 1990 and Mercedes had had a controlling interest in the firm since 1999, moving to full ownership in 2005. Even so, when this booming grand tourer was announced as a pure AMG car in 2009, the grudging nature of the parent company's relationship with AMG was still being reflected in the afterthoughtish positioning of their initials in the car's name: Mercedes-Benz SLS AMG. Even when Mercedes re-entered Formula 1 in 2010, there was no acknowledgement of AMG's existence: it was the Mercedes GP Petronas Formula 1 Team.
Had the global financial crash of 2008 given M-B the heebie-jeebies about the future of high-end motoring and convinced them to keep AMG well below the radar? Whatever the reason for their hesitation, by 2012 everything had changed. AMG's credibility was being enthusiastically embraced not only in the renamed Mercedes AMG Petronas F1 Team but also in M-B's performance-oriented car range where those three evocative letters have completely barged 'Benz' off the nameplates.
The heritage of AMG may have been somewhat under-leveraged but the arrival of the SLS in 2009 showed that Mercedes had no qualms about looking a lot further back in its own history books. The SLS was touted as a spiritual successor to the W198 300 SL Coupe, the aluminium bodied, spaceframe chassised supercar that was the Bugatti Veyron of the mid-1950s, and to a less widely acknowledged extent, the Mercedes-McLaren SLR, just over 2,300 of which were built between 2003 and 2010.
The unenviable job of following two cars separated by fifty years with a 'beauty and the beast' machine of enduring quality that would be loud but in a tasteful way, that wouldn't be shown up on a track, and that could also conceivably be put on show in a museum was entrusted to Brit Mark Fetherston. The SLS's straked vents and long nose paid due homage to the 300 SL. The classic aircraft vibe established by the stacked-on cockpit and upright windscreen was mirrored in the SLS's weight. Although you might not believe it if you saw them side by side, the SLS was considerably lighter than Mercedes' contemporary (and by that time ironically named) SL (Super Light) sports car. Thanks to its outer body and main structure both being fashioned from aluminium, the SLS (Super Light Sport) was 350kg lighter than the equivalent R230 SL 63 AMG and around 130kg lighter than the Mercedes-McLaren SLR.
It was a heavy hitter in the engine department though. Like the SLS itself, the M156 6.2 litre engine was AMG's first ground-up V8. It broke cover in 2006 in the 507hp W211 E 63 AMG saloon and quickly achieved legendary status for power and noise but also, less happily for AMG, for broken headbolts and soft camshafts. In the SLS the motor was revised at the top end (valve train and camshafts) and switched to dry sump lubrication. Now producing 563hp and recoded as the M159, it went like stink and sounded amazing. It still sounds brilliant, oozing a lazy thunder that's dreamily out of sync with the ridiculous speeds you're doing.
In 2011 the Roadster variant was launched at Frankfurt with the same mechanical spec and an extra 40kg to carry, not bad for a variant that traditionally adds a lot of weight. Contributing to that was a triple-layer fabric roof rather than a metal one. The near-200mph top speed and sub-4sec 0-62 time were practically unchanged and the driving experience was actually preferred by many, at least in part because of the less insulated exhaust rumble. Airscarf neck-level heating and a reversing camera were standard and the Roadster also ushered in the new option of AMG Ride Control sports suspension featuring three damping modes, Comfort, Sport and Sport Plus.
A year later the SLS AMG GT was released with a 20hp power boost to 583hp, some transmission and suspension upgrades, new alloy and diamond quilted leather options, and Bang & Olufsen surround sound as standard. A 740hp/740lb ft Electric Drive version of the SLS was unveiled at the 2012 Paris show. It was the first all-wheel drive fully electric supercar but despite the extensive use of carbon fibre it still weighed more than 2.1 tonnes and cost £360,000. Worldwide sales didn't reach three figures.
The SLS AMG Black Series debuted in 2013 as a 2014MY car and was the horniest SLS yet. It might not have looked that different to the regular car but in fact it was heavily revised for track and tyre-frying duties with a wider track front and rear, wider bodywork, new wheels and carriers and 50 percent stiffer suspension, while its engine - the last hurrah of the normally aspirated big-inch Merc V8 - had a new higher rev limit of 8,000rpm and a new peak of 622hp (up 70hp) at 7,400rpm thanks to new valves, a new intake, bigger bearings and a new oil system.
The big story however was the Black's weight of 1,550kg, representing an eye-rubbing cut of 70kg. Replacing the stainless steel exhaust system with a titanium one accounted for 13kg of that. The same amount was saved by using a carbon fibre housing for the propshaft. Switching from a lead acid battery to a lithium-ion one trimmed another 8kg. The gearbox was carried lower and the gearchange was faster. Whereas normal SLSs had a mechanical limited slip diff the Black Series had an e-diff.
Racing seats replaced the standard perches, carbon ceramic brakes were standard, and there were new, posher dampers and a fixed rear wing. The bonnet was made of carbon fibre. Torque was slightly down to 468lb ft at 5,500rpm but the mix of light weight, heavy power and a slightly lower final drive ratio ensured electrifying performance. It was a specialist vehicle: 150 were built. If you'd been one of the fifteen who stumped up £230,000 for one of the UK right-hand drive cars and kept the miles low you'd be laughing all the way to the bank today, as our selection of used cars at the end of this piece will show.
The last SLS was the AMG GT Final Edition, available as either coupe or Roadster. Only 350 were made in total across both variants. They were mechanically identical to the SLS AMG GT, but carbon fibre was used for the black vented bonnet, splitter and Black Series fixed rear wing.
In 2014 the Mercedes-Benz SLS AMG was discontinued and replaced by the Mercedes-AMG GT. The monster V8 was replaced by a 4.0 twin-turbo V8 with an extra 20hp, the same torque, a sharpened transmission, and a lot of trim upgrades and plenty of new options. It went round the Nordschleife in under 7.5 minutes. In that same year David Coulthard, who was involved in the development of the SLS, set a new world record for catching a golf ball in a speeding car. Well, it kept him off the streets. The GT S version famously became F1's Safety Car in 2015.
Gloriously, the 6.2 V8 made a comeback in 2015 as the power unit for the GT3 race version of the GT. The big motor was chosen over the 4.0 for its reliability and user-friendliness. With that endorsement thundering in our ears, let's get ready to rumble with a look through the SLS used car offering.
SPECIFICATION | MERCEDES-BENZ SLS
Engine: 6,208cc, V8, 32v
Transmission: 7-speed automatic, rear-wheel drive
Power (hp): 563@6,800rpm
Torque (lb ft): 479@4,750rpm
0-62mph: 3.9 secs
Top speed: 197mph
Weight: 1,620kg
MPG (official combined): 21.4
CO2: 308g/km
Wheels: 9.5x19 (f), 11x20 (r)
Tyres: 265/35 (f), 295/30 (r)
On sale: 2009 - 2015
Price new: £160,000
Price now: £105,000
Note for reference: car weight and power data is hard to pin down with absolute certainty. For consistency, we use the same source for all our guides. We hope the data we use is right more often than it's wrong. Our advice is to treat it as relative rather than definitive.
ENGINE & GEARBOX
When the SLS was announced in 2009, going on sale in the UK in mid-2010, Mercedes claimed that its 6.2 litre V8 (with over 120 different parts marking it out from other AMG 6.2s) was the most powerful naturally aspirated engine ever made. It also turned out to be the last AMG to feature a naturally aspirated engine. It's a hell of a tool and a strong contender for best V8 ever.
Although the AMG Speedshift 7-speed transmission is a dual-clutcher it does have certain quirks. An upshift while slowing down (which although it sounds a bit mad can happen in certain circumstances) can result in an unseemly forward lurch. Shifting generally is relaxed or even non-existent if the gearbox decides in its Germanic wisdom that the downshift you've just called for is unwarranted. Porsche's PDK box is more responsive. The Speedshift did have a 'Race Start' launch control feature, but even with that in play replicating the claimed 0-62 time of 3.8sec wasn't easy. Enhanced AMG factory software for the gearbox is very much worth having. Resetting the positioning sensors can extend the life of the clutch.
The SLS did very well overall in comparison tests with other exotica such as the Aston V12 Vantage, Porsche 911 Turbo S and Ferrari 599 HGTE. If, despite that, you felt a little light on power, firms like Weistec would supercharge your SLS to an easy 825hp.
There was a problem with the propshafts of 135 of the GT S cars that were built in mid-2015 for the 2016 model year. The shaft could part company with the engine/trans flange with predictably disastrous results. There have also been very rare reports of radiators needing to be replaced and electrical wiring needing to be fixed, but generally the moving parts have an excellent reputation for reliability and quality.
Most owners keep the servicing (recommended annually irrespective of mileage) within the M-B dealer network as factory servicing isn't as expensive as the appearance of the car might indicate. Allow £500 for an A service (though it could be under £350) and £1,000 for a B (which includes transmission oil and spark plug change and which again should leave you with some headroom) using Mobil 1 as the recommended lubricant.
CHASSIS
If you judged this particular book by its cover you might expect a cruisery sort of experience but an SLS will almost certainly over-deliver on your expectations. The perennial compromise between ride softness, steering feel, stability and driving precision is nicely judged. Only the vastness of the bonnet and uncertainty about where the car actually finishes tarnishes the user-friendliness.
None of that hampers the car's behaviour though. Despite the massive V8 up front, its rearward position in the bay - all the metal is behind the front wheel centreline - means that 53 percent of the SLS's weight is over the driven rear wheels, a useful attribute when there's 478lb ft of torque to transmit. From your place in the driving seat, your head isn't that far ahead of the rear wheels but it's a long, long way from the fronts.
Standard SLS wheels had seven-spokes. If you wanted to save money you could pick five-spokers. If you wanted to splurge, ten-spokes were available. Carbon-ceramic brake discs - 402mm on the front and 360mm at the rear - were an £8,140 SLS option. Activated by six- and four-piston calipers respectively, these ceramics were claimed to boost braking power by 40 percent. Standard steel discs are around £1200 for the front pair, with pads at just under £250.
BODYWORK
The SLS bootlid, which incorporates a spoiler that extends at 70mph and retracts at 50mph, is made of plastic, but just about all of the other body panels are aluminium. Most cars seem to have been painted in either white or some form of grey paint. Imola Grey (shouldn't that be Red?) was one of lower-priced paint options at £1,755. Alubeam Silver was considerably dearer at £8,570 but it does look amazing. Magno paints sell well too.
Like the original 1954 300 SL, the gullwing door design is one of the biggest standout features of the SLS. It plays a big part in keeping coupe values high in relation to those of the roadster. Mercedes' decision not to fit the doors with power closing mechanisms was reportedly down to the 40kg-plus weight of the motors that would have been needed. It is a bit of a stretch to the handle once you've dropped into the seat, so wise owners tend to grab it on the way down. The doors themselves are surprisingly light. Check the gaps though because aligning them is very difficult.
If you're a shy, retiring type you may feel slightly embarrassed by door-based theatrics in (say) an Aldi car park, and if you're trying to get in or out of your SLS in heavy rain there's going to be water getting in on account of the fact that you're moving a big chunk of the roof out of the way and most rain falls vertically unless you're in Newcastle. At least there's a replaceable leather panel on the sill to protect your pants on the way in. Some Roadsters have had odd roof sealing issues.
The boot is a very decent size but a profusion of lumps and bumps do rob the space of some of its usefulness. Wonderfully, the SLS has a interior boot release with a constantly pulsating light on it so if Fat Tony shoves you in there for a quick drive to the cement works you can pop the lid and jump out at the first red traffic light. The SLS also has the equally wonderful old-school Mercedes trick of a bonnet that opens almost vertically for easier engine access. The headlights are bi-xenons, with LEDs everywhere else, including for the fog and reversing lights.
INTERIOR
You sit low in an SLS, but taller humans would be banging their head on the coupe roof if it was all at the same height as the central section. Luckily it isn't: the gullwing door design allows for roof cutouts above the seats which provide a few invaluable extra inches of skull space.
Facing you are two deliberately traditional looking silvered-face main gauges either side of an info screen and a strip of shift lights. The steering wheel rim is a combination of leather and Alcantara, which is nice, but the central boss is plastic, which isn't quite so nice. Nor are the centre dash buttons, some of which control no functions whatsoever. That feels a bit mean in such an expensive car.
A rack of chunky knobs on the central stack includes a manual control for the rear spoiler, handy when you fancy exploring the aerodynamic envelope at 10mph in the Aldi car park. The upright windscreen is quite shallow, as are the door windows, so the cabin isn't exactly flooded with light or especially easy to see out of. With that in mind, some may view the hefty prod that the throttle needs to get the car moving in reverse as a useful safety feature.
The seats will be in single- or two-tone designo leather. Black and red or black and porcelain are well-liked combinations. The sporty buckets that came in the Black Series cars aren't necessarily seen as a good thing in non-Black cars, but GT and Final Edition cars without the diamond quilted cabins are likely to be sniffed at by buyers.
Two carbon interior choices were available, the £2,995 Carbon Fibre Trim (which essentially replaced the aluminium trim on the centre console) and the Carbon Fibre Interior Package which for an additional £3k put carbon on the inner sills and seat backs. Having those wide sills for crash protection purposes means that there are no door pockets for storage. All you get for that is a pouch on the rear firewall and a string bag in the passenger footwell.
Some of those with a fine ear thought that heavy bass tracks didn't sound that great through the SLS subwoofer on earlier cars. If you wanted to cure that by ticking the box for the B&O surround sound system that would cost you over £5,000. If the start button doesn't work for whatever reason you haven't totally lost because there's a secondary slot for the ignition key in a box at the back of the centre console.
PH VERDICT
You don't see many SLSs in the UK. That's maybe because, at not far short of two metres wide, it's broader than an S-Class and therefore not that especially well suited to smaller British roads. Forget all that though and concentrate instead on the fact that an SLS offers a superb blend of performance, driveability and sheer class. Then try and buy one. That's where your problems start.
After heavy initial depreciation, SLS values bottomed out in 2014 at around £100,000 before picking up strongly. Most of the cars now on sale in the UK seem to be early (pre-2012) models, suggesting that owners of later cars are enjoying them to the extent that they don't want to sell them.
One thing's for sure: there's no such thing as a cheap SLS. As noted earlier, Roadsters buck the normal trend by being more affordable than the gullwing coupes despite being quite a lot rarer (SLS GT Roadsters being the exception as it's believed that there are only two of them in the UK). Sure enough, the most affordable SLS in the PH Classifieds right now is indeed a Roadster, this basic black 27,000 miler from 2012 coming in at just under £105,000. This almost identically mileaged coupe will however cost you £30,000 more. Just shows you what doors can do.
The rarity and attitude of the 15-off right-hand drive Black Series is spectacularly reflected in used prices. Here's a 5,000-miler that's being advertised at a specially cheap Covid price of £749,990. Final Editions go up for big money too. There are no British ones for sale at the moment but there's an 86-mile example in Germany at 420,000 euros. That dealer also has a Roadster version at 5,000 euros less.
You might see cars advertised as SLS Studio Performance Editions but this is not a name recognised by marque specialists and could mean nothing more than 'here's an SLS with some random bits in it'. The cost of these won't be reflected by a hike in the car's value. If you find a Matte Black Edition Roadster for sensible money let us know because they only made five of those for the Japanese market and we'd like to throw a big party with the resale proceeds.
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