With just two milk bottles worth of displacement, the Mercedes-AMG A45 S is the worldโs most powerful four pot. But does it have too much power?
TL;DR: Powerful but grown up compared to the old A45; feels like a proper member of the AMG family.
What we like: The instant urge; the ride is smoother and more composed; drift mode for when youโre on a race track.
Whatโs not so great: The price and the fact itโs still just an A-Class.
Mercedes-AMG A45 S Specifications
Price $93,600+ORCs Warranty 5 years, unlimited kilometres Safety Not Tested Engine 2.0-litre turbocharged four-cylinder Power 310kW at 6750rpm Torque 500Nm at 5000-5250rpm Transmission 8-speed Automatic 0-100km/h 3.9 seconds Dimensions 4445mm long; 1850mm wide; 1403mm high; 2729mm wheelbase Turning Circle 11.54m Kerb Weight 1635kg Boot Space 370-1210L Fuel Tank 51L Fuel Type 98RON Fuel use 8.9L/100km (claimed)
Iโm a bit of a numbers man, and the figures on the latest newcomer to emerge from AMGโs Affalterbach home base are enough to get lovers of performance cars a tad excited.
They also demonstrate how far engine development has come over the past decade or two. The Mercedes-Benz A45 S AMG has a full 310kW of power โ from a 2.0-litre engine.
Yep, the same capacity used in Corollas and Mazda3s manages to muscle up with some very desirable sports car fare. Granted, thereโs a sizable turbo bolted on to kick things along. And it does cost $93,600, which is some $15K more than the model is steps in for (in Australia we only get the more powerful S model).
But that 310kW is also a very serious number thatโs worth putting in perspective. Weโll start with a German thoroughbred in the form of the Porsche 911. Sure, Porsche does some brutally ballistic 911 models that would smash the A45, but the most affordable 911 Carrera makes 283kW from its 3.0-litre twin-turbo six-cylinder. Thatโs around 10 percent less than the feisty Merc.
Go back a couple of decades to the 280kW from the screaming 3.5-litre V8 in the Ferrari F355 of the late 1990s. Again, less than this humble hatchback. And the last of the Holden Commodore V8s โ with a 6.2-litre V8 โ made just 304kW.
Yet this little hatchback from Mercedes-Benz trumps the lot, while backing it up with a luscious 500Nm of torque. Unsurprisingly itโs the most powerful four-cylinder ever unleashed on a mainstream production car. That it resides in a sensible-looking five-door hatchback reinforces the split personality of a car thatโs got a few doses of wild mashed into its DNA.
Switching it up
Blame it on that engine. Far from a tricked-up version of the old 2.0-litre turbo in the A45 โ itself an accomplished performance car – the new one (codenamed M139) has undergone a major transformation.
The head has been spun 180 degrees, in turn moving the turbo from the front of the car to between the engine and the occupants. Crucially, that turbo now sits near the exhaust, reducing the distance air has to travel from compression to big bangs.
And AMG engineers have also done plenty of work elsewhere, unleashing another 500rpm to the top of the rev range.
Freeing up
Itโs made a decent difference. Whereas the old A45 felt stilted towards the top of its rev range, the new one keeps punching towards its redline (just beyond 7000rpm), unleashing more power along the way. Dial up Sport+ or Race modes and the gearshifts sharpen noticeably, with purposeful jolts between ratios.
And while the engine always has a rortiness to it โ with some associated vibration โ it picks up some cracks and pops in those more serious modes. Still, much of the initial acceleration โ the claimed 0-100km/h sprint is 3.9 seconds โ relies on that all-wheel drive system.
Thereโs a twin-clutch eight-speed auto with a fiery launch control system that kicks things off nicely. It leaps furiously from a standstill, giving off less heat as speed increases. And it can drink like a V8 if you utilise all that fire, easily slurping 12-14 litres per 100km of premium unleaded when driven enthusiastically.
Settling down
The biggest change with the A45 AMG is to its general demeanour. The old car was a bit naughty-kid-in-the-corner in the way it bumped and jiggled its way around anything but smooth hotmix.
The suspension was more go kart than everyday hatch, which hurt its chances of ending up on some driveways. The new one is bigger, more comfortable โ and far more mature in the way it gets around.
Even in Sport+ the adjustable dampers donโt try to give you double vision. Yet youโve still got the immense cornering ability, helped in part by super sticky 19-inch Michelin Pilot Sport 4 tyres.
The clever all-wheel drive system diverts plenty to the rear but still claws its way out of tight corners beautifully. The way the A45 fires out of a hairpin reasserts its performance credentials.
Itโs point and shoot motoring, in some ways missing some of the nuances of more focused performance cars, but making up for it with sheer pace.
Rear bias
Those wanting more of an adrenalin hit can dial up the drift mode. Itโs not the sort of thing youโd unleash on a public road, in part because thereโs so much grip that youโd have to be seriously pushing on to unstick the rear-end with almost all the drive heading to those back wheels. Its addition, indicative of the efforts AMG has embraced to ensure this iteration is more closely aligned to others within the AMG family.
Rather than a tricked-up hatchback, itโs looking and driving more like a genuine AMG. Even the design moves that along. The new A45 gets the latest vertical grille bars, for example. And the front wheel arches are unique to the A45, widened to accommodate the fat tyres and enormous brakes (yes, theyโre strong).
Even inside thereโs loads more AMG flavour. The Alcantara-trimmed steering wheel with flattened sides and a flat bottom is terrific. Body hugging seats are beautifully trimmed, in line with others in the AMG family.
And the electronics have been stepped up, now including a Super Sport display mode for the digital instrument cluster (Super Sport tries too hard to be funky and futuristic; weโre happier with plain old Sport).
Hold your horses
That said, all is not rosy in the world of hyper hatches. Cruising at 100km/h on a country road has those Michelins roaring away into the cabin noticeably, forcing you to raise your voice to keep the conversation flowing.
And it is still an A-Class hatchback, which is good for those who like to fly under the radar but not so flash if you have to explain to your non-car-enthusiast friends why you blew 100-large on a hatch.
But, hey, itโs all part of the appeal of a hatchback thatโs grown up nicely, bringing lashings of feistiness in an easy-to-live-with package. One that has taken the whole hot hatch thinking to the next level.