Porsche 911 Turbo S vs Mercedes-AMG A45 S – battle of the all-weather superstars
As the weather turns, we go head to head in two very different all-weather super star performance cars
There is a theory that there’s only so much performance you can use on the road. That when it comes right down to it, you’re only on full throttle for a few seconds at a time, so while the potential may be huge, be it in terms of grip, horsepower or both, in reality only a percentage of it can be deployed. I’ve seen it in action, from the seat of a Porsche 911 GT3 while tailing a Ferrari Pista, the Ferrari’s 700bhp unable to ‘gap’ the 500bhp Porsche. This is on sinuous driving roads, of course, not autobahns.
So I’m hopeful that the fat rump of the 911 Turbo S is not going to get much smaller in the windscreen of my Mercedes-AMG A45 S, despite the chunky little Merc having a deficit of over 200bhp. We’ve ambled down this road a couple of times, dep ed Adam Towler and I, while evo photographer Aston Parrott trains a long lens on us from the top of the valley, so we have an idea of its twists and turns. When we get Aston’s radio message to say he’s got the shot, I’m expecting the 911 to take off.
And it does, leaving the A45 and, it seems, that theory choking in its wake… But there are only short straights, there are tight corners and there is Armco on the right and hillside on the left. This is a road that demands you stay in your lane, within the white lines, and that should help the narrower, lighter Merc. So why isn’t it?
I already know: it’s because the Turbo S’s astonishing, explosive performance can exploit any straight to devastating effect. I’m flat-out in the Merc, upshifts popping keenly, yet the Porsche zooms away in a surreal fashion. It’s as freaky to see as to feel. But I still reckon the Porsche won’t have the upper hand everywhere. Further on, I hit the brakes later than I have been to claw back ground, knowing the wide-hipped 911 needs to be carefully, precisely threaded.
The Mercedes doesn’t have the sustained stopping power of the Porsche and its carbon-ceramic brakes, but it has another advantage: you can chuck it in and sort it out as you go. Even in its latest form, the 911 still behaves like a 911. With so little wiggle-room, you don’t want to provoke it on the way in and you want to have it pretty much straight before unleashing another massive slug of performance. Hustling the Merc into the corners gains back a few yards and, encouraged, I go for an even more ambitious braking lunge into the next series of flick-flack, left-right turns, unintentionally finding the limit of the A45’s composure.
The Mercedes’ discs bite positively but the chassis gets all squirmy and vague beneath me so I can’t tell exactly what’s going on. Alarmingly, the rump of the Porsche is reversing towards me, its brake lights blinking like hazard flashers.
Despite such efforts it remains a fruitless pursuit, because as soon as the road unwinds into the next short straight, the Turbo S is gone. I have to accept that while the A45 S can cover ground at a terrific pace, even when everything is stacked in its favour it will never seriously pressure the Turbo S. But although the A45 and that theory may have just taken a beating, that’s only one aspect of this twin test.
I’ve lost count of the number of tests won by the 911 over the years. Tests against more powerful, bigger and more expensive rivals, tests against aspirants with the same power or layout or objective… and every time the same result. Why? As well as hitting bullseyes in performance and dynamics, the 911 has always been remarkably efficient, handily sized and, for rivals, annoyingly practical, with two small rear seats and a front boot that seems deeper than the car itself. It also delivers character and engagement when you’re just ambling and you can park it anywhere, so really it’s no mystery why it has long been the default everyday sports car.
By extrapolation, ever since the first four-wheel-drive 911 Turbo arrived back in ’95, it has been the default everyday supercar, the supercar for all seasons. The 993 variant was a revelation, the Turbo’s reputation for being fast but frightening transformed by all-wheel drive that made 402bhp astonishingly exploitable. It became an instant icon.
Sure, it wasn’t as sharp or absorbing as the lighter, simpler RS but it quickly cemented its place in the range as the 911 with massive performance that could cover continents in comfort. Power and sophistication have increased with every generation until here we are in 2022 with a 641bhp Turbo S that hits 62mph in 2.7sec and 205mph. The non-S Turbo has a piffling 572bhp and manages a tardy 2.9sec and 199mph.
The status quo has been upset, though. Just after the 992’s introduction we group-tested the 911 Carrera and – shock, horror! – the 911’s recent run of road test wins came to an end. It felt like a pivotal moment. The 992 was a beautifully polished product but the physical scale of it and the lack of character from the new turbocharged flat-six and the car in general left us a little underwhelmed; it didn’t feel like a 911 until you were properly pushing on.
That doesn’t mean that the status of the Turbo has been similarly downgraded. The key thing is that the changes from 991 to 992 suit the Turbo better than they do the base car; there’s only one body, the wide body (aka the Turbo body), and of course the loss of engine character through the fitment of intake-muting turbochargers is just business as usual. But it’s so big. I’ve had a few supercars on my driveway and the Turbo S is almost as wide as they come, and with its size comes weight: a not-inconsiderable 1640kg unladen. In part that explains why it needs the grip of 20-inch wheels at the front and 21s wearing 315-section Pirellis at the rear.
The 200-mile journey to the photo location answered a few of the questions regarding the Turbo S’s touring ability. Its seats are comfortable enough, though I never did discover how to adjust the lumbar. Maybe it was in a sub-menu of the touchscreen, the buttons on which, for me, are too small. One of the few hard keys, for the damping, was soon pressed, because although the ride is quite busy it also feels too free, with an unchecked lurch over bigger bumps. The sportier damper setting sorts it, the car a little firmer but usefully flatter and not to the detriment of comfort.
Historically, the Turbo got firmer after Nissan put a bat up Porsche’s nightdress by claiming a stellar Nordschleife lap time for its new R35 GT-R. Before then there was a feeling that the Turbo’s Ring time was a figure of no more significance than peak brake temperatures on the Stelvio or mean intercooler pressures at Arjeplog. But once Nissan had destroyed it, Porsche seemed spurred into getting more track speed out of the Turbo, inevitably making it more taut.
Mind, with almost 650bhp to contain and deploy, it would have gone that way anyhow. Just a small squeeze of the throttle in the Turbo S induces a massive, almost instant outpouring of urge from the twin-turbo flat-six. Ambling along, the first time you give it full throttle is nuts; the dual-clutch gearbox seems to magnify the response, the thrust ramping up as it drops rapidly through the ratios to find the optimum gear, the engine then unleashing the full torrent of power and torque. It’s so responsive it caught itself out when I nailed it out of a roundabout: the ’box found first and full boost arrived so quickly that the engine clattered into the limiter before it could get second gear.
Simply travelling briskly is what the 911 Turbo should excel at. There will be other models in the range for those happy to trade some ride quality for dynamic precision, so the Turbo should be one of those cars in which you feel less obliged to nail it through the corners. More of – dare I say – a point-and-squirt car, the four-wheel drive there to help deploy the performance with little fuss in all weathers rather than to strengthen cornering ability. The performance itself should be immense but with an appealing, huge-striding elasticity to it. The latter the Turbo S has – if you manually select high gears and make the motor dig deep – and it sounds good, too, with the optional sports exhaust, which is refined and quiet in Normal but gutsy and growly in Sport.
The ride can be a bit lumpen on some surfaces though, leading us to wonder if the standard Turbo set-up, as opposed to the optional 10mm-lower sport suspension fitted here, is more rounded. The steering isn’t especially sharp or detailed and the same goes for dynamic feedback, so it feels as though you’re not benefiting greatly in that regard.
Can the (deep breath) Mercedes-AMG A45 S 4Matic+ teach the Porsche anything about everyday, all-weather performance then? Well, it impressed the pants off us at eCoty in 2019, delivering like no Mercedes fast hatch before it. It’s not short on grip, being four-wheel drive, and it’s not short of grunt either. In fact, as a measure of how far we’ve come, the A45 extracts 415bhp and 369lb ft of torque from its 2-litre, four-cylinder engine. That’s more power and only marginally less torque than produced by the 993 Turbo’s 3.6-litre, twin-turbo flat-six (402bhp and 398lb ft). And with its eight-speed dual-clutch gearbox, the Merc gets to 60mph in 3.9sec, nearly half a second quicker.
Given the A45 S’s cross-spoke alloys, front winglets and high-mounted tailgate spoiler, I never fail to be gobsmacked by its ritzy interior. It carries on the black-and-yellow external colour theme, the emphasis thankfully reversed, but with a dashboard, centre console and wheel finished in polished metal and piano black that is gloriously glitzy, plus mood lighting that gives it a Hollywood Boulevard look at night. It manages to make the Porsche’s cabin look a bit low-rent when it really isn’t.
A difference in quality is immediately apparent in the steering, the underlying feel of the A45 no match for the solidly engineered tactility of the Turbo S. There’s a raw, looser edge to the A45 and an unvarnished sportiness in how it sounds, the growl of a potent 2-litre four quickly subsumed by the sound of air being ingested and compressed as the short gearing of the DCT gets the A45 smartly up to speed. It feels potent and agile and also unexpectedly supple for a hatch with so much ready torque at its disposal.
In fact, the A45 S is not only smoother riding than the Turbo S, it’s also more refined, better isolating its occupants from road noise and feedback. I reckon I could write the i-SPY Book of Major Road Surfaces after the trip down in the Turbo, identifying them by the level and quality of tactility through the wheel and floorpan. You certainly appreciate smooth asphalt in the Porsche.
One thing the two cars share is a usefully accessible drive mode button hanging off the steering wheel. The Merc’s firmest damper setting – Race – is fine for choppy B-roads, the ride still rounded but with better vertical control. There’s the option to tailor most of its dynamic character, apart from steering weight, which is a shame because the effort required at the chunky rim is always a fraction heavy for me.
It’s an intense drive in Race with the full-on exhaust blare and keenest throttle and upshifts, yet there’s still a calm edge thanks to that supple ride. It’s brilliantly effective, the energy from the engine an endless rush, perfectly managed by the DCT gearbox and effectively deployed by the four-wheel-drive system and Michelin PS4 tyres. After a few miles there is, you feel, not much that could show it a clean pair of tailpipes on demanding roads like these…
Perhaps the most unexpected aspect of the A45’s dynamics is its willingness to oversteer. There’s minimal understeer and if you keep the throttle pinned through a long corner the drive will gradually shift to the rear, yet when the back end pushes out you correct it instinctively. ‘You’re never a prisoner to that weight somehow,’ says Towler, ‘never searching for traction or dealing with understeer. The way it’ll exit under power properly sideways has to be experienced to be believed.’
Push the Turbo S and it becomes more 911-like, more tail-heavy in feel, so you wind back its stability control with due consideration for the avalanche of near-instantaneous torque that could be unleashed. While Towler has the A45 opposite locked mid-corner like a Vatanen Escort, I’m catching a jink of the 911’s hips right at the exit in PSM Sport. Even that feels brave, the Porsche still driving hard and exploding from the damp corner like a champagne cork. Having learned how much throttle unsticks the rear, I do one run with PSM off, purely in the name of science.
Thing is, you don’t have to take risks to make sensational pace in the Turbo S. Just driving neatly, dipping into its enormous performance and leaning on the terrific grip is enough to see off pretty much anything else on the road. ‘It feels more like low altitude flying than driving,’ says Towler, adding: ‘You only sustain its full-on pace for a short period before a fuse blows somewhere in the grey matter.’ The Turbo S is an astonishing piece of engineering, no question; it’s just a shame it doesn’t amble along as effortlessly and quietly as you’d hope when you’re not going for it.
The A45 S is not in the same league in many respects but we always come away impressed. It only ever feels short of grunt when it encounters a ground-based missile like the Turbo S. In reality, it’s shockingly fast too, but what’s remarkable is that it gives up its performance so freely and in a way that, at times, looks way more dramatic than it feels; the tail slipping out under power is no more threatening than lift-off oversteer in a front-drive fast hatch.
Then there’s the ride. Suppleness is a key element in the A45’s pace, adding a calmness to its dynamics that in turn makes you relaxed, and after an exciting day in the hills, it makes the Merc cosseting and stress-free on the motorway run home. If we’re honest, the ride could take a bit of stiffening. You know, just for a bit more control when chasing supercars. Details, mere details. Truth is, while you might want more from an all-season performance car, the A45 S gives you all that you need.
|Mercedes-AMG A45 S||Porsche 911 Turbo S|
|Engine||In-line 4-cyl, 1991cc, turbocharged||Flat-six, 3745cc, twin-turbo|
|Power||415bhp @ 6750rpm||641bhp @ 6750rpm|
|Torque||369lb ft @ 5000rpm||590lb ft @ 2500-4000rpm|