Our view:
Is there a 'sweet spot' for power when it comes to hot hatchbacks? It's a debate which has often been mooted over the years by car fans and one which has grown in vehemence as what appears to be open warfare rages - with manufacturers using peak outputs as their main weapons of mass-production destruction. But the thing is, a hot hatch should be exploitable, it should be affordable and it should be capable of harnessing its maximum power on the roads. You might get away with a 'mere' 250hp, if you can deploy it right. But, on the other hand, surely faster is better, right? So isn't the solution to keep tipping more horsepower into the hot hatch mix?
It's clear that some companies subscribe to this latter view, because the 21st century has seen the rise of what is sometimes termed a 'hyper-hatch'. And yet, having tried the few vehicles that fall under this breed, we've always been left a bit cold by them. The two main proponents of this theory are, of course, German: namely, Audi and its often
underwhelming RS 3; and Mercedes-AMG with its counter-punch
A 45 4Matic. We're not trying to say that any RS 3 or A 45 we've ever driven has been actively poor, you understand. It's more that they have had the propensity to be lacklustre. Overpriced. A bit too focused on speed above all else, such as chassis finesse. And yet, so powerful that to even try and use their upper reaches would be to invite an extended stay at Her Majesty's pleasure.
The A 45 itself really improved during the midlife model facelift of the previous-generation model, when it gained adaptive dampers. It felt more fun to steer, albeit you needed a track to really get the best from its underpinnings and there was still a suspicion that - at road speeds - it wouldn't give up any particular thrills. So can this new one possibly deliver what the previous, 381hp A 45 couldn't deliver? Especially as it has gained even more power and has become even more expensive as a result?
Well, relax, AMG fans. Because this new A 45 S is an absolutely blinding car. And not just because it has that phenomenally powerful 2.0-litre engine up front. That Mercedes is reliably getting 211.5hp-per-litre from a blown four-pot like this is quite astonishing. Bear in mind it isn't simply the engine from the 'lesser'
A 35 but turned up to 11; rather, it's a completely new unit called the M139. It's also an utter belter. The way it delivers its power, the throttle response it has, the sensation of minimal turbo lag - this is a truly stunning power unit.
Which, in turn, is allied to a cracking eight-speed dual-clutch gearbox and Mercedes-AMG's excellent 4Matic+ all-wheel-drive system. This what gives the A 45 S such outlandish speed, because it's all well and good having a nuclear bomb of an engine, but if the power it develops is having to negotiate its way through a recalcitrant gearbox and then is ultimately fruitlessly spun away at the wheels once it arrives, it's a waste of time generating a colossal output in the first place. No such concerns about the Merc's drivetrain, though, as neither the 8G-DCT nor the 4Matic+ allow for an ounce of slop in the delivery. You put your foot down in the A 45 S, it instantly rips away at the road ahead, snarling fiendishly as it goes, and goes bloody chuffing quickly. And yes, we said 'snarling'; you will not hear many better turbocharged four-cylinder soundtracks in production cars from any era than the noises this powered-up A-Class makes.
So it's fast and it's loud, and it's incredibly poised too. It feels a rear-driven car more than anything, the back sliding quite freely in Sport+ - remember, the A 45 S has a Race mode with a Drift function in it, if you don't feel it's oversteering enough on the public highway;
ahem... - and that immediately gives it a greater degree of lower-speed, accessible fun than its predecessor. In essence, you don't have to be driving the door handles off the A 45 S, and therefore flying way above the speed limit, to have a laugh in it. The steering conveys accurate, rewarding information about what the tyres are up to, while both the body and the wheel control are operating at the highest possible standards for the class. The AMG doesn't skitter about on lumpier road surfaces and so you can deploy as much of its power as you dare in a wide range of circumstances and atmospheric conditions. It is every bit as fast, across the board, as its startling on-paper stats would have you imagine.
And yet, it's daily useable too. We did more than 550 miles in a week in the A 45 S Plus, where it not only thrilled us immensely on quieter back roads, but it also eased away the drudgery of long motorway schleps. Furthermore, screwing 421hp out of a forced-induction 2.0-litre has its advantages when you're not making the turbo ram as much air down the Merc's gullet as possible, because you'll actually get decent economy from this thing without too much effort. We saw an outstanding best economy figure of 37.7mpg on a motorway slog from south of London to the top of the East Midlands, and over the entire week the A 45 S turned in a remarkable 28.2mpg. Considering how it was driven during those precious moments when nobody was looking, that latter number looks like nothing little short of witchcraft.
It's also a splendidly upmarket creation. You don't have to have the lurid big wing of the Plus model, as there's a 'regular', more discreet A 45 S without the AMG Aerodynamic Package available from £51,195 if you so desire. However, we think the styling of the Plus works really well, especially if toned down with a tasteful, sedate colour like Denim Blue (metallic colours are £595). And if you don't have the Plus grade then you don't the AMG Performance Seat High-End Package, which gives you a set of some of the best bucket chairs in the business up front. Indeed, the whole cabin of the A 45 S is smashing - that beautiful Widescreen Cockpit display is one of the better heavily digital interfaces in the automotive industry, as it's mainly controlled by the two haptic pads on the spokes of the steering wheel, while the fit and finish of everything you look at and operate is exemplary.
So the 421hp A 45 S is clearly markedly improved from the old 381hp model, and we liked that car a lot as it was. However, it's not
quite a glowing report card from start to finish for the Mercedes-AMG. For starters, £57,165. That's a... not-inconsiderable amount of cash, isn't it? Sure, the A 45 S offers supercar pace across all weathers in a practical hatchback body, so it possesses a unique blend of talents (or, some might say, a
very particular set of skills?) that probably merits a near-60-grand asking ticket, but at the same time... fifty-seven thousand pounds. For a hot hatch. Yes, the German missile is brutally rapid and incredibly thrilling. But, to a degree, so is a
Hyundai i30 N, or a
Renault Sport Megane Trophy, and they don't cost anything close to £40,000, never mind the wrong side of 55 large.
It's not so much the price which bothers us, however, but the ride and refinement. In the main, the A 45 S rolls along quite bearably, considering it is sitting on 19-inch alloys and it needs to be able to keep a tenacious grip on the road when it is flexing its muscles. But with variable dampers as part of the standard equipment, it's a shame that the Comfort mode can't offer up more of, well, precisely
that; comfort. Like so many German high-performance machines of recent years, the AMG rides with a taut and lissom grace, as long as you're doing in the vicinity of 70mph. Yet in the zone of 30-50mph, it can amplify minor imperfections in the surface of the tarmac to a degree that really isn't necessary. Add in quite an elevated amount of tyre roar from the Michelin Pilot Sport 4 tyres that come fitted OEM and while we were happy to do 550 miles in the A 45 S in a week, we can think of other fast five-doors that would have been more refined and pleasurable to travel in for long distances.
No matter, though; the Mercedes-AMG's rolling comfort levels are tolerable enough in the main and its noise suppression of other contributors, like the four-pot engine and wind flowing around the cabin's exterior at speed, are kept to a suitable minimum on a trailing throttle. Plus, the Plus comes with an exquisite Burmester Surround Sound system for its mammoth fee, so you can simply drown out the excessive chatter of the PS4s with that if needs be.
Therefore, we have to mark the A 45 S down as one of the greatest hot hatchbacks of the moment, and also possibly that we've seen from any manufacturer so far. It is of course the ultimate expression of what a conventional hatchback car can do if it has taken way too many performance-enhancing drugs, and for some its indisputable metric superiority over any other fast C-segment machine will be more than reason enough to lay out the huge expenditure to own the A 45 S Plus. Yet what's really special about it is not its devastating straight-line speeds, but rather the fact it offers a cohesive and engaging driving experience at saner velocities. And, in fact, that it feels every bit as special and edifying to be in as one of AMG's more
outlandish creations, despite the fact it is 'only' a hatchback and it 'only' has a four-cylinder engine. Slightly crumbly ride quality and marginally too-noisy tyres aside, there's precious little to dislike about the Mercedes-AMG A 45 S Plus and plenty enough to adore; it's a brilliant performance car by any measure.
