Mercedes-Benz SLS AMG: The definitive test

Some cars look better when you’re close enough to feel the heat from their engine bay and hear the tick-tick-twang-tick of their cooling exhaust system. The Mercedes SLS AMG is a perfect example. I’ve seen it from every angle in photographs, and with its bolt-on cabin, over-long snout and hammerhead headlamps, it hasn’t wowed me. Yet moments after it pulls up on the legendary Brooklands banking in the soft early- evening light, I’m smitten.

At close range you can see the interplay of the lines, the fine detailing and the sculpting, especially around the rear with its flush-fitting pop-up boot spoiler. There’s drama, too, when the gullwing door rises to reveal a riotous red, black and silver cockpit. But the other feature that’s hooked me in even before I’ve dropped into the driver’s seat is the noise. I’m a sucker for a tasty V8 and, even on a light-throttle overrun, the SLS delights with a rumble and crackle like distant thunder and lightning as unburnt fuel ignites in the exhaust.

Of course, this evocative soundscape is entirely engineered and not the result of hefty carburettors and huge valve overlap, but it shows that the engineers at AMG truly love the traditional offset-crank V8. They’ve gone to great lengths to ensure that the 6.2-litre V8, which they designed specifically for Mercedes’ AMG models, sounds at its very best in the SLS, the first car for which the Affalterbach outfit is entirely responsible. I just hope their passion for exploitable rear-drive handling, ably demonstrated by the CLK Black, shines through on UK roads. It will need to, because the breadth and depth of talent we’ve gathered as a welcoming committee is formidable.

What struck us from the first time we drove the SLS late last year was just how hardcore and capable it was, and that has informed our choice of rivals. Technically it stands toe-to-toe with the Ferrari 599 Fiorano, sharing among other things the front-mid-engined, rear-drive transaxle layout and being constructed largely from aluminium, so we have a 599 HGTE here. The SLS is not as expensive as the £221K Ferrari, though. At £157K it’s midway between two V12-engined Astons, the DBS and the V12 Vantage. It’s the more compact, sportier AM we’ve chosen. Completing the front-engined rivals is the £235K Bristol Fighter, the 8-litre, V10-engined rarity that had the gullwing-door super-GT market all sewn up before the SLS came along…

Alternative supercar layouts are available, of course, represented here by Audi’s mid-engined R8 V10, the bargain of the group at a mere £105,810, and the stubbornly rear-engined 911 Turbo S, the most potent Turbo yet, fresh from Germany and in at a heady £123K. Both are assisted by four-wheel drive.

By the time Jamie Lipman has shot the last frame of the day at Brooklands (these days home to Mercedes World), the orange sun has slipped below the horizon. There is now the small matter of 240 miles between us and our hotel in North Wales. It’s at times like this that the GT abilities of a car become most alluring.

Most cosseting is the Bristol, with its softly welcoming seats, supple ride and intergalactic gearing; its gargantuan 525bhp V10 ticks over at less than 2000rpm at the motorway limit. It feels born to this, the very definition of gran turismo (the automotive concept, not the PlayStation game), though you do find yourself wishing its narrow, aerodynamic shape cleaved the air a little more quietly.

Least relaxing are the Aston and Ferrari. On the upside, you’re unlikely to nod off in either on the motorway, or stray out of lane, because the noise of their wide tyres hitting cat’s eyes is dramatic. ‘They sound like minor explosions beneath the wheels of the Vantage,’ says David Vivian later. They elicit sharp reports in the 599 HGTE too, as do expansion joints, making concrete carriageways tiresome, but overall the Ferrari’s ride is less unyielding; its high-back, pseudo race seats have more padding (and adjustments) and its suspension breathes a little more. The Porsche suffers road noise, too, but as Henry Catchpole says, it can have your eyes wide open in a moment – just nail the throttle and feel the twin-turbo power of the flat-six hit you like a runaway train. A spike of adrenalin is a useful pick-me-up if you’re tired…

Do these cars sacrifice a little comfort for control? Will they hit their stride when we get onto the flowing, challenging roads that criss-cross North Wales’s wild places, or are they merely less resolved? The Audi has soaked up the four-hour schlep with ease and, on the more interesting roads that finally deliver us to our hotel in Betws-y-Coed at well past midnight, has hinted that it has the feel and precision to deliver when the road gets tricky. Like a few others here, it also has a firmer damper setting to call upon, whereas the Mercedes, unfashionably, features fixed dampers. However, this solus setting so far appears to cover all the bases rather well, providing a firm but fair town ride, decent motorway comfort and good control when pushing on. Catchpole, who has more experience of the SLS than anyone here, reckons the key is that its aluminium monocoque is very stiff, giving the suspension a solid platform to work from. Just the thing for the roads we’ll be visiting in a few hours’ time.

I'm not sure that everyone else in the hotel appreciates AMG’s enthusiasm for the big-hearted V8 when the SLS barks into life at 7am and the deep, open-valve blare of its tailpipes reverberates off the high walls of the car park. As is the modern, ECU-managed way, the tone dampens down considerably after a short while, just in time for the Ferrari’s Enzo-derived V12 to take over with an urgent, high idle, followed by the 5.9-litre Aston V12, and another 20 cylinders once the Audi and Bristol get going. Amidst all this, the soft croon of the Porsche’s flat-six barely registers. Visually it’s not much of a draw either, but it’s a car you underestimate at your peril.

With the Merc already bagged for some photographic work, I slip behind the wheel of the Turbo S. The exterior doesn’t shout ‘£123,000’ and the interior is no more dramatic than that of a base Carrera, but feel the quality. The Audi R8 feels pretty special in the first few yards, but the way the Turbo S moves is just as impressive, the ride polished, the steering delivering satisfying weight and directness. Sure, there’s a little hesitation getting going as the twin-clutch gearbox sorts itself out, but once rolling the automatic shifts of the seven-speeder are seamless. No question, this car is shot through with integrity.

On the smooth, looping section of the A5 that climbs out of Betws-y-Coed, it is settled and assured. Its engine may be slung out the back, but the Porsche tucks into the corners with a calm, neutral keenness that suggests the engineers at Weissach have suppressed the 911’s natural characteristics so that it’s less intimidating and its tremendous performance is more exploitable. It might be ‘only’ 30bhp up on the stock Turbo, but that car is astonishing on full boost and, with 523bhp and cool morning air, the S edges the experience that bit closer to the zone marked ‘loopy’. (At Millbrook it will nail an incredible sub-3sec 0-60mph time…)

Straights appear to evaporate and, with the corners coming in quick-fire succession, what I want now is a little more control over the gears and to employ some engine braking. Pushing the Sport button sets the gearbox on a higher state of alert, and on Sport Plus it drops a few ratios too, but it sounds frantic. For total control it’s best to slip the gearlever across to Manual and use the simple new + and – paddles.

The corner grip the Turbo S finds is staggering, as is the amount of torque the chassis can deploy on the exit, and I’m wondering if anything else here could cover the ground as quickly. But there’s something missing, and as we head up into the hills and onto more challenging asphalt, that vital something becomes very obvious. It’s feedback. Despite the occasionally turbulent surface beneath its wheels, the Porsche remains locked on line, but the steering is numb and there’s precious little information through the seat too. You know it’ll grip, but it’s not as much fun as being involved and feeling connected.

This leg of the evo Triangle is as tough a test as you’ll find and I worry that the Aston might feel too connected given how uncompromising its ride can seem. Like the original concept car, this particular V12 Vantage is an odd mix of hardcore and luxury, its pearlescent baby-blue paint, bling alloys and leather-lined cockpit contrasting with carbonfibre bonnet vents, lightly treaded Pirellis and sports bucket seats. The message that this is a proper drivers’ car hits home the moment your backside hits the seat – there’s minimal padding and no backrest angle adjustment as such; instead the whole shell tilts. Matching the tone set by the seat, the steering wheel has a slim, suede-covered rim, and sprouting from the transmission tunnel is a fat, soft-edged, manual gearlever.

As always with the Vantage, initially it’s hard to finesse the pull-away because the clutch biting point is vague and there’s very little feel to the throttle action, but once you’re off the Aston impresses. There’s a direct, connected feel through the steering and a willing front end that brings instant confidence, backed up by a tight ride. There have already been a couple of gripes about the gearlever being mounted too far back, but as those same drivers concede, the flexibility of the outsize V12 is such that gearchanges are almost optional, third or fourth sufficing for most situations.

Up the pace on this tricky road and occasionally on the way into a turn the Aston does feel like it’s got a big engine up front, while unleashing every last ounce of torque in the lower gears can make the rear axle squirm mildly, even on the straights, but the car feels alive beneath you and in your hands. Lean on the front a bit more and it pushes back, the P Zero Corsas biting into the warm asphalt, and on corner exits the rear hooks up and shifts a few degrees out of line as the V12 hollers, all in balance. If the Vantage is much slower than the Porsche it doesn’t feel it, partly because throttle response is instantaneous, though the way they get things done is utterly different.

‘I like the Aston,’ says Vivian, back at our muster point. ‘It’s uncomplicated. The Porsche on the other hand is a very blunt instrument. Compared with the GT3 it feels like it’s from another planet.’

Catchpole agrees: ‘It’s as if Porsche thought, “We can make this car much faster and we’ll suppress all of the natural 911 traits.” And they have, but there’s no character either.’

Vivian’s a big fan of the Audi, though: ‘It’s superb along here,’ he says. Having began yesterday behind its wheel myself, I’m not surprised, and as the SLS is yet to join us, it seems a good time to see if it’s as impressive here as it is in town and on the motorway.

Our mid-engined rival to the SLS was meant to be a Gallardo LP560-4, but the Lambo eluded us and this R8 V10 was a late substitution. Despite having racked up over 19,000 miles, it feels and looks virtually box- fresh, apart from its performance… which is sensational. This is the most potent and free-revving 5.2-litre V10 we’ve tried in an R8. In fact, it feels almost Lambo-strong.

Driving the R8 well takes little effort, thanks to its light controls, smooth clutch take-up, tactile and positive gearshift and polished engine mapping. It’s also one of the few cars with adjustable dampers that feels right in both settings. On this road the firmer one ties the wheel control down that bit tighter, giving more positivity but without spoiling the ride, which is almost magical. The R8 feels in charge of this road, the 518bhp V10, with its instant, elastic delivery and nape-prickling, lung-squeezing 8500rpm top end, shoving it along as its suspension absorbs the worst of the bumps and its steering lets you know how the chassis is coping.

Yet the R8 V10’s dynamics have a definite comfort zone. It starts to drift out of it when you feel the nose get light and the tail, laden with V10, get a little heavy. This can happen in fast sweepers or in abrupt direction changes in tighter corners, and it feels like a cue to cool it. Unlike some of the front-engined cars here, the mid-engined Audi isn’t a chuck-it-in-and-sort- it-out sort of car.

‘It’s true that it’s a bit of an eight-tenths car,’ says Catchpole, ‘but like the Aston, you don’t have to be going fast to enjoy the experience.’ He’s right: there’s great pleasure to be derived from an unhurried approach, being in the correct gear and using the engine braking rather than the brakes to flow along a road, and still making great progress.

The SLS pulls up, its doors lift slowly and, as happens every time they do, within a couple of minutes it has brought some passers-by to a halt. Drop into the driver’s seat, swing your legs over the sill, then reach up and tug the door shut. The cockpit has a quite simply designed, traditional flavour with clean instruments that appear pressed from steel plate. And then there’s the centre console. This houses a whole arsenal of buttons, including a rotary dial offering four settings for the seven-speed twin-clutch transmission, another for ESP Sport and off, one marked ‘AMG’ which summons up your personal preferences, and a glowing red one which starts and stops the engine.

Hit the red one, feel and hear the 563bhp, 6.2-litre V8 erupt, drop the stumpy, fat-headed gear selector into D, squeeze the throttle and… after a brief pause… you’re away. It’s perhaps the SLS’s least enjoyable characteristic, the tardy responses of its gearbox. It’s a beefed-up version of the Getrag twin-clutch transaxle used in the Ferrari California, but it feels less impressive here. It makes smooth, snappy full-throttle upshifts when left to its own devices, but use the paddles and there’s a delay between when you pull and when it shifts.

That apart, the SLS feels at home here almost immediately. There’s an easy, natural feel to the well-weighted steering and the ride is nicely judged, offering fine body control and the right degree of compliance. The SLS steers with accuracy, too, and so although it feels like a big car as you set off, you don’t think about its width again. Until, perhaps, you realise you’re picking gravel from the road’s edge.

It feels brilliant over the faster, more flowing sections, dealing tightly with crests and compressions, all four corners planted, while the big V8 feels mighty. The tuning tweaks wrought for the SLS, the choice of seven ratios and the car’s reasonable kerb weight (1713kg with a full tank of fuel, by our scales) combine to produce terrific throttle response, and wrung out to 7000rpm it sounds determined and feels about as potent as anything else here. Power and control: a compelling combination.

Seems you can hear confidence in an engine note. As I pull back into our lay-by, Catchpole saunters over, smiling slightly. ‘It’s very good, isn’t it?’ he asks. Certainly is, but the best here? There are more cars and more roads to try yet.

It’s surprising how big the Ferrari looks, even compared with the Mercedes. Perhaps white doesn’t help but it’s hard to believe that the Aston packs much the same hardware in and casts a much less substantial shadow. Inside the 599 there’s a less luxurious and more, well, technical feel with its heavily sculpted surfaces and blend of glossy carbonfibre, smooth leather and Alcantara. It seems odd to find race-style seats with electric adjustment in a few of these cars, but the HGTE’s wing-backs are quite superb and eminently tailorable.

Twist the key, thumb the lipstick-red starter button on the steering wheel and when the 611bhp 48-valve V12 catches, it sounds like it’s right in there with you. Lovely. Pull back on the slender right-hand paddle to select first, squeeze the throttle and you’re reminded that this is an automated manual gearbox with a single-plate clutch. It bites more abruptly than a twin-clutch type, which is fine, but the lumpy, yawn-shift way it works its way up the gears in Auto mode is almost crude. There’s no option but to take charge via the paddles and finesse the shifts with the throttle.

Dynamically, the last HGTE we tested (evo 142) was a sharp, edgy car, but this one isn’t. As we’ve already discovered, the tyres react strongly to cat’s eyes but this firmness isn’t a general demeanour. In fact, there’s an unexpected amount of vertical and lateral compliance in this HGTE chassis that robs it of crispness and focus. The 599 turns eagerly like the Aston but when the car’s not loaded up the sharpness of its lighter steering can seem undermined by an excess of give in the chassis, and the traction control is pretty busy, too.

For a few miles the epic reach of the 6-litre V12 goes unexploited, the line of five red shift- lights embedded in the top edge of the steering wheel unlit. The last HGTE we drove took some learning and this one starts to make sense when you pick up the pace. Switch the manettino to Race, impose your will on it and the slack seems to get hauled in. The 599 now goes just where you point it, and, when you get the shift- lights fully lit on the straights, the sound and fury are awesome.

I find myself tucked up behind Catchpole in the Turbo S on a particularly challenging bit of tarmac and a mile or so later the 911 is a few lengths further ahead. But only because it’s sucking so much dirt off the road and flinging it at the Ferrari. The 599 has the measure of the 911, being better composed and predictable through lumpen corners, which look like a wild ride in the Porsche. Seems that the Turbo S can’t hide its 911-ness at the limit, bucking and side-slipping at the rear where the 599 merely scuffed its nose and jinked its rear wheels a fraction. ‘That corkscrewing motion was really uncomfortable,’ says Catchpole, frowning.

I’m not quite sure what to expect from the Bristol. Vivian, who has logged more engine hours on the dials of Fighters than I have, prepares me for the experience by suggesting I think of it as choosing a pair of handmade leather slippers rather than the latest hi-tech trainers. As always, he’s spot on.

The Fighter’s open gullwing doors sit higher than the SLS’s, so there’s less chance of clouting your head on them, but you have to remember to pull the door down with you as you slide across the wide sill and into the driver’s seat, because once seated you won’t be able to reach it, unless you’re Mr Tickle. Pull straps are provided but most owners remove them, as here, because they’re unsightly.

There’s a bespoke and very individual feel to the Fighter. It’s a narrow car but doesn’t feel it, offering generous elbow room, and visibility is good, especially over the shoulder thanks to the canopy-like rear window. The facia is simple and quite classy with dark, machine-turned metal trim, and there are extra dials tucked beneath the steering column and, aircraft-style, into the roof (including the one for engine hours), where there are also lots of switches.

Twist the key and the 8-litre, Viper-derived 525bhp V10 fires and assumes a bassy, snuffly, off-beat idle. Get rolling and you discover clarity of steering that’s V12 Vantage-like and an ability to smother lumps and bumps that’s Audi‑ish, but really it’s not like anything you’ve ever driven, unless you’ve driven an old Bristol. The characteristics that define them define the Fighter; performance is monumental (the V10 churns out 350lb ft from tickover) and administered through long gearing that lends the Fighter an effortless, deceptive turn of speed, while dynamically it’s faithful and accurate, with strong traction, but it’s a car that you guide and coax rather than bully and cajole. That would be most unseemly.

‘You either get it or not,’ says Catchpole. ‘I understand that, but I don’t think it’s for me.’

The moment to decide the finishing order is rapidly approaching and the fabulous road on which we find ourselves come late afternoon is the perfect final location: it has delivered many etched-in-the-memory drives. Somehow it brings out the best in any car, and the better the car, the richer and more rewarding the experience.

First to go is the Bristol. Much as we love its individuality and admire its ability to eat up the miles, along this road you’re left in no doubt that it sits at the GT end of the scale. It simply doesn’t indulge you like the others.

Driving the Porsche here, on the other hand, is like a game of dare. The Turbo S sticks to the smoother sections like it’s on slicks, and how soon you dare step on the gas to summon up full boost becomes the challenge. It’s incredibly, neck-strainingly fast, a longitudinal and lateral G-fest. Yet loading the Turbo with so much power and allowing it to be readily exploited does come at a price, and it’s feedback and steering feel that get jettisoned. ‘It doesn’t seem like a 911 until you get to the edge of the technology that’s been put in place to stop it feeling like a 911,’ says Vivian. ‘It’s the best mini-Veyron yet, though.’

There’s no doubting the depth of the 599 HGTE experience along here. It really gels on this road, shrink-wrapping itself around you, sending a stream of detailed feel through the wheel rim and allowing you to modulate the throttle and use the V12’s power to work the rear tyres right to the edge of their grip. Yet this example feels different to the last one we drove along here and, if you’re not pushing it, then its dynamics seem to lose focus. Over to Catchpole: ‘It’s got a wonderful sense of drama about it, though I’d prefer mine in black. I just wish it felt great even when you weren’t on it.’ Metcalfe, who’s really bonded with the 599, reckons the SLS has got its work cut out to beat it, but he’s alone on that one.

We’re all agreed that the Audi is fantastically accomplished – ‘Unfazed by just about anything,’ says Vivian – and is both tactile and easy to drive. Supercar fast, too. Yet it’s not on the top step. ‘It’s odd how quickly you become blasé about it,’ says Catchpole. It’s almost as if it’s too good, as if dynamically it’s almost too transparent. Mostly it’s superb, and you pretty much know this within a few miles. Perhaps there’s simply not enough of a challenge, or maybe it’s that the front-engined, rear-drivers here allow you to do more with them.

There are obvious flaws in the Aston, notably its gearlever position, excessive road noise and, for some, the lack of lumbar support, but that didn’t stop it charming the pants off most of us. It’s handsome but there’s nothing especially clever about it; it’s simply a very appealing rendering of the time-honoured formula of a big engine in a small car.

‘Not the last word in sophistication or finesse but properly fast and taut. “Honest” sums it up nicely,’ says Vivian. Catchpole is a big fan: ‘I love its compactness, especially compared to the Ferrari. It feels like you can adjust both ends at the same time. And whatever gear you’re in, it’s effing fast and sounds great. I could imagine living with it and enjoying it on all sorts of roads.’

It has to give best to the SLS, though, which nails the dynamics and delivers long-distance ride comfort and refinement, too. Add in deep-chested, characterful performance and traffic-stopping looks, and not even a tardy twin-clutch transmission can stop it.

‘Top of the pile by dint of being the most accomplished all-rounder here,’ says Vivian. ‘Arguably, it’s got the best chassis of all – so incredibly composed and well tied down. It looks great, too.’ Metcalfe isn’t completely won over, though: ‘It’s fantastically competent but I wonder if you’d have more fun in the Aston. And why does it feel so heavy?’

‘It could perhaps have a smidgeon more steering feel,’ reckons Catchpole, ‘and the gearbox should be snappier, but AMG has created a superb drivers’ car.’

There’s no doubt about that. The SLS feels made for this last road of the day, as if it was developed to master every corner, crest and camber. It flows along, connected but filtering out anything distracting, and settles into corners quickly. The sense of poise is terrific; it’s as if the car slows down the action so you can relish it and weigh up your options. Pour on the power and you almost feel the rear treadblocks moving on the road surface, squeeze some more and the SLS is steering oh-so subtly on the throttle. And all the while you’re accompanied by the authentic sound of a classic, hi-po big-block V8, right down to the overrun crackle. No question, the SLS delivers a drive to remember.

Jaguar XKR 75

You won’t be able to buy production versions of this rather special XKR in lime green when it goes on sale in July, but when you want to stand out at the Goodwood Festival of Speed, you can’t beat an eye-watering colour. Today, however, we’re more interested in deeds than looks, and although it would have been unfair to drop the XK into a test that has ceilings of £230K and 611bhp, both we and Jaguar were intrigued to see how this most potent XK would compare with cars ostensibly out of its league. And besides, this is the Jaguar’s patch, the roads where the development team fettled this special XK.

It’s called the XKR 75, it’s a limited edition (the clue’s in the name) and it’s the most focused XK yet. The driving force behind it is Mike Cross, Jaguar’s chief engineer of vehicle integrity, and it started out as an out-of-hours ‘what if?’ project. The sportiness of the XKR got a good leg up a year ago when both the XKR and XFR got the new 503bhp supercharged V8 and an electronic locking differential, and Cross knew that with just a few choice adjustments the XKR could be taken to an even higher level.

With detail calibration changes and a freer-flowing and acoustically tuned exhaust, the 5-litre V8 croons like the SLS and pumps out a Turbo S-matching 523bhp, while on the chassis side there are increased spring and damper rates, reduced ride heights (15mm front and 10mm rear) and retuned adaptive damping. There are also lightweight, diamond-cut forged alloy wheels bolted to new, beefed-up wheel hubs that offer better geometry control.

It sounds great, the V8 loud and confident at start-up, rounded but edgy at idle, and once the wheels are rolling the XK feels recognisably Jaguar-like; light on its feet, its ride supple and absorbent. Up the pace and the V8 feels gutsy, the shifts of the ZF auto smooth and crisp, and it steers keenly, the chassis feeling very biddable. One thing Cross and his team have worked on is the throttle action, and there’s now a positive feel where there was once a soft, approximate response.

Referenced against the cars assembled for the test, this XK lacks little in potency and has a top-drawer transmission. The surprise is that it has the softest set-up of all and on some of the more wicked bumps runs out of travel. ‘The idea was to create a car that you could drive to the Nürburgring, set a good lap time, and drive home again, and we have,’ says Cross, adding that this prototype has set a Ring lap time of 8.01 with some traffic. Does that make this leg of the evo Triangle a tougher test than the Nordschleife?

As far as it goes, the XKR 75 is a fine thing and we’re sure the 75 will be snapped up when they go on sale in July, price to be announced. Ever so gradually, Jaguar is toughening up the XK and shifting perceptions of what a properly sporty Jaguar can be. We reckon it’s time for the grand gesture: a 911 RS-style XKR.