AMG 45 S vs Nissan GT-R: New hot hatch vs used supercar

How expensive can the humble hot hatchback become before the concept loses all meaning for drivers of typical means? Renault recently let its ambition run rampant with a version of the Mégane RS that, in its most pulverisingly hardcore, carbonfibre-wheeled form, costs more than £72,000. It's an awe-inspiring asking price, and too much, because if most of us wanted an impractical machine that prioritised involvement for that sort of money, we'd have the new Porsche 718 Cayman GT4 or a lightly used Lotus Exige Sport 410. And it wouldn't require much head-scratching to come to that realisation.

But now Mercedes-AMG is having a go. Its effort is called the A45 S, and all £50,570 of it (£56,570 for the option-laden Plus driven here) is being chased across the sort of patchily damp, unevenly cambered B-roads we all know and love. Fast? Freakishly so – genuinely supercar-baiting. Expensive? Evidently, but had you bought a Delta S4 Stradale from Lancia in 1985, it would have cost you £55,000, translating to £167,000 today, so along with the RS Trophy-R, we're hardly talking unprecedented sums. And unlike in those cars, you do at least get a second-row bench behind the deep buckets in the AMG.

Very much like the Lancia, there's a whiff of homologation about this new Mercedes, even though – with no A-Class motorsport activity since the previous generation competed in the BTCC – it's nothing of the sort. Compared with the £38,000 A35, designed to go up against the Volkswagen Golf R et al, the A45 S is a different animal: broader wings, wider tracks, brackets welded in to stiffen the sleek, snouty body and a truly world-class powertrain with recording-breaking specific output. This car even has canards, ridiculously, and four 82mm tail-pipes to visually balance out the huge – and optional – rear wing.

The Nissan GT-R also has a wing, not least because it can hit 196mph. Road test editor Matt Saunders has brought one along because it poses an enviable conundrum for the would-be A45 S buyer.

When the R35-generation GT-R arrived in 2007, Nissan perpetrated a memorable strategy balls-up by underpricing it to an almost comical degree. It cost £56,000, undercutting rivals in performance and pedigree by light years, and the bargain price solidified Godzilla's reputation as one of the great giant-slayers.

Nissan remedied its mistake, and the GT-R has since become steadily more expensive; the new track-day Nismo version costs an astonishing £175,000. But today you can buy a lightly used, post-facelift example for the same money as a new A45 S. And that leads us to today's burning question: when it comes to these giant-slayers, could you honestly bring yourself to buy the hatchback over the supercar? Would you be a fool to even consider it?

Many people will consider it, on account of the GT-R's age. First built at Nissan's plant in Tochigi Prefecture, where even the police force enjoy the local speciality, fundamentally the current GT-R is now long in the tooth, and nowhere is that more evident than its interior. Equally, its primeval road presence is undimmed after all these years, and it's difficult to think of many cars that need less of an introduction in terms of performance.

In my 2017 guise, the GT-R's twin-turbocharged 3.8-litre V6 makes an unstressed 562bhp and 470lb ft, put to the road through a BorgWarner twin-clutch six-speed transaxle and Nissan's ATTESA E-TS driveline. With two lengthy propshafts, the system is generously rear-biased but can go half-and-half for the torque split as necessary, and the GT-R remains among the quickest ways to string several counties together short of using aviation fuel.

These newer cars supposedly put more of the 'GT' in 'GT-R', too, with softer damping and better acoustic insulation, but on noisy Dunlop tyres this example still feels reactive and raw, if not to the extent that owners of the latest Mercedes-AMG C63 S would be up in arms. Litchfield, the world-famous specialist where this car is for sale, nevertheless tends to swap the Dunlops for Michelin's excellent Pilot Sport 4S rubber.

Finished in Sun Yellow, the little A45 S is nuclear fusion on wheels: a concentrated dose of massive energy. It's up against the GT-R here, but a compact footprint and the fact the closed-deck, hand-assembled, AMG-grade engine makes fully 416bhp from merely two litres and then delivers it to all four corners makes it more of a successor to the old Mitsubishi Lancer Evolution.

There's no full-time four-wheel drive or manual gearbox, though. Instead you get an eight-speed dual-clutch auto and a set of clutches in the rear axle that can siphon all the available torque (meaning up to half what the engine is making at any given moment) to either side. The engine has also been swivelled so the exhaust ports and twin-scroll turbo now face your kneecaps and the intake looks forwards. This set-up also shortens various air channels for better response. An electronic tickle of the mass-produced M260 engine in the lesser A35 it is not.

From what Saunders says after following in its wake, it's clear that the AMG has the measure of the GT-R in terms of point-to-point pace on the road – which is remarkable. Whether that would still be the case on a bone-dry day, when the coupé's larger contact patches and more balanced layout could make the difference, seems academic. You'd need to be travelling at speeds not so much unprintable as incomprehensible to really show much difference.

More surprising still is that the Mercedes' primary weapon isn't its mighty but strangely workmanlike engine. We expected it to rock up with an absolute head-banger of a powerplant paired with a chassis so uncompromising it would be almost impossible to live with. Not so. Its blend of body control and pliancy at speed is an exhibition, and likewise the relatively plush low-speed ride is unrecognisable from the old A45.

Where the GT-R's chunky body can find itself a half-step behind the road surface, the A45 S has an almost telepathic awareness of what's going to happen next, to the extent that you may get a vague sense of futility. Any corner, seemingly at any speed: you can feel the clever driveline triggering differentials and flexing torque even as the nose whips in. And while the stubby tail will swing, what the car really wants to do is stay perfectly neutral and fling itself forth, with the rear axle mucking in to an enjoyably detectable degree. Short of crassly overriding physics, it doesn't do understeer.

With 200kg less to carry, despite the two extra doors, the AMG has the GT-R licked for agility. And while its speed-sensitive steering is less consistent and can become twitchy on choppy surfaces, it possesses life and heft – traits carried over from AMG's fine-steering bigger-hitters.

In comparison, the GT-R needs some winding up, and in more ways than one. You need to acclimatise, because with all that mechanical clonking, gentle turbo whistle in the background and delicate but acute accelerator response, the car feels shot through with an authenticity that can be mildly intimidating even at sedate speeds. Also, the cabin is on the tight side and the Naca ducts in the bonnet bulge up into your field of vision, although as rivals have grown, the GT-R no longer seems to spread across its lane so thuggishly.

Only when you really begin to explore the performance – the car's potential, and how much of it you might exploit between here and there – do you realise that the GT-R, even in its twilight years, can still draw you deeper into the driving experience than so many others, including this phenomenally effective AMG. Fail to read the road and it will hop and skip at times, and despite the point-and-squirt reputation, the combination of its long nose and rear torque bias means it's only with a sense of excitement and trepidation that you begin to brake later and chase the throttle earlier. Then you start to find its groove. In this weather, it will slide freely, sometimes unexpectedly, and to get the most out of any GT-R you need to show respect and finesse, which you don't always with the A45 S. This makes it an addictive car.

How likely is it that any committed GT-R shopper could be tempted to buy an A45 S instead? Bluntly, there's next to no chance. As much as the performance continues to represent superb value for money, the Nissan's heritage and aura are what give it almost inimitable appeal at this price, and its rawness is worn as a badge of honour. Inevitably, the hot hatch's slick usability also undermines its sense of occasion, if only a little.

Those of a more open-minded disposition are strongly advised to drive the AMG. Plenty will scoff at the price, but you need to forget about traditional hot hatches and coldly consider what this one can do. The performance is simply extraordinary, and the fact it comes from an engine of only conventional displacement means the handling isn't made nose-heavy by additional cylinders. This M139 unit is also smooth and linear (although not by any means immune to turbo lag), which is some achievement, given the stress it needs to withstand. The new gearbox is a touch slurpy in comparison with the best dual-clutchers, but it's easily good enough, and the car also does surprisingly well in other core areas: driving position, pedal weighting and, let's not forget, passenger space.

So please excuse the cop-out, but there really is no loser on this occasion – because both cars are exceptional in many ways, and because both manage it despite pariah status. The GT-R has to share its badge with all manner of soulless metal and the A45 S will always carry the baggage of being a hatchback, but they're giant-slayers both. The GT-R's spirit, the more unfiltered nature of its talent and the eventfulness of even a short drive ultimately give it the edge, but few A45 S owners will regret their choice. This latest AMG – a car more identifiably AMG than hot hatch – is clearly worth the money.

The world of used GT-Rs

Never mind the £63,000 GT-R driven here: a quick skim through the online classifieds shows it's now possible to get hold of an early GT-R for less than half that. Assuming you can find one with a traceable and reasonably caring history, the arguments for such an outrageous, sub-£30,000 purchase are straightforward: 478bhp, 434lb ft, amusingly brutal kerbside presence and true driver appeal for VW Golf GTI money.

At the other end of the spectrum, post-2017 GT-R Nismos, with their GT3-spec upgraded turbos, enormous carbon-ceramic brakes and perforated bodywork, still go for more than £100,000.

What's important to remember is that Nissan has continuously refined and improved the GT-R, often without fanfare between major facelifts. Not only that, but also the original cars need servicing every six months or 6000 miles; Nissan moved to annual servicing for 2012, so you're better off with the most recent car possible.

Whichever GT-R you plump for, the robustness of the powertrain is legendary – standard engines will reliably take around 770bhp, while the 'box can handle 630lb ft – and with specialists like Litchfield, there's plenty of support. Lastly, because Nissan keeps pushing up its prices, residual values tend to stay strong.

The best GT-R for your budget

2013 GT-R, £42,995: This is a second-phase GT-R, so it benefits from better gearbox mapping and more power: 542bhp. With GT-R culture being what it is, standard earlier cars are rare, but this seems a good example with relatively few miles. It looks epic in pearl white.

2019 GT-R Prestige, £68,000: Considering the GT-R is now priced from £83,955, this 1960-mile example looks inexpensive. Alongside the visual tweaks, third-phase cars made 563bhp and received stiffer bodies to go with softer damping settings. There's also improved NVH and interior upgrades.

2018 GT-R Track Edition, £89,995: The Track Edition shadows the Nismo, sharing its seam-welded shell, wider track and hollow anti-roll bars. This one has been fettled by Litchfield to make 630bhp. Arguably representing an R35 sweet spot, it's still good value.