The old A45 AMG was fast but flawed. The latest A45 S rewrites the hyper hatch rulebook. Here’s why

The Wheels Verdict: Expecting the new Mercedes-AMG A45 S to be similar to older models? Think again. It’s been massively improved car compared to its predecessor. With that comes a significant price rise, but if you want the world’s most capable hyper hatch, you’re looking at it right here.

The Mercedes-AMG A45 S?

In the past, the AMG revolutionised the fast hatchback market with its A45. That car was raw, edgy and uncouth but gave a enticing look for what was possible. That potential has finally been realised in the ultra-polished 2020 A45 S. It’s a perfectly civil hatchback with more pace and power than a V8-engined Audi R8 supercar.

Putting the Mercedes-AMG A45 S up to the test.

Growing curiosity for the reviews of the A45 S from its international launch and this was the first chance it had on Australian roads. With that in mind, we took it to one of the very toughest we knew, the queen stage of Victoria’s high country. If the A45 S could perform here, then it could shine anywhere.

What we think…

Now we have this new A45 S, riding on the more advanced fourth-gen A-Class chassis. Power has stepped up yet again, the latest model making a dizzying 310kW at 6750rpm. Torque? How about 500Nm at 5000-5250rpm? The result is a claimed 0-100km/h time of just 3.9 seconds. We verified exactly that figure during independent testing using the standard launch control, so it doesn’t require any fancy footwork to achieve.

In order to extend the selection of the A45 S, the team at Affalterbach clearly thought long and hard – and at a very early stage – about how this latest car would go down a road. This is absolutely fundamental stuff; the basics of suspension tuning, transmission response, driver feedback and power delivery.

Firstly, the car had to ride well. “It’s an improvement in every perspective,” says AMG boss Tobias Moers. “There’s more comfort, more rigidity in every way, so we put a lot of effort into the body in white. There’s lots of reinforcement.” The three-stage adaptive dampers cycle through Comfort, Sport and Sport+ settings and the first two are exploitable on any road, with Sport+ best reserved for smoother surfaces. In Comfort, there’s a genuinely expensive-feeling polish to the damping, with noise pathways into the passenger cell decently suppressed.

Also helping the A45’s body control is a far slicker transmission. The old seven-speed dual- clutch has been replaced by an eight-speed unit, and it’s not so much the extra ratio that transforms this installation, more the smarter software logic. With the old ’box, you were often denied what appeared viable downshifts and the transmission would sometimes do odd things like throw in an unwanted upshift just as you stepped off the gas to go for the brake approaching a corner.

The AMG Speedshift DCT 8G transmission, to give it the full moniker, is a very different box of cogs. It’ll perform double-declutching theatrics in Sport+ and partial ignition cuts during upshifts, but when you’re not driving it like a berserker, it’ll slur between gears, doing a decent impression of a torque converter auto.

Finally, there’s the issue of driver involvement. I don’t offer any apology for talking about this at length. Other aspects of the A45 S have been covered at length elsewhere. If you’re here, you want to know how it drives. Want an infotainment review or a deconstruction of lower dash-materials quality? That’ll be along later.

Key to the new A45’s dynamics is the AMG Torque Control system, effectively a pair of separately acting clutches on the rear axle that allows 100 per cent of the torque directed rearwards to be sent to either side. Drive the A45 S hard on a challenging road and it’s clear that AMG has got a lot right. The steering is crisp and accurate, although its two weighting modes are not individually selectable. More on modes later. The brakes are excellent, too, with massive 360mm discs up front clamped by six-piston callipers. Body control is tight, front-end grip imperious and turn-in tenacious.

That the engine punches well above its 160.5kg weight is clear. Moers again: “The reason is that we’re going to use that engine for further applications which are not necessarily east-west applications.” In other words, this hand-built M139 unit, which still adheres to Affalterbach’s one man, one engine credo, is going into bigger AMG models in future.

Combine propulsion and poise in equally generous parts and you have a car that can demolish a challenging cross-country route. And this is where I have an issue with the A45 S. It’s refined enough to function as a daily driver, but despite that civility it doesn’t mean it’s a car you get a lot from at modest speeds. For all its smarts, it’s hardly a tactile overload. Even the pops and crackles from the exhaust have been muted this time round.

Punch the accelerator, and this thing just gets even more exciting. With some effort, you can pivot the car into a corner on the brakes or with a throttle lift, but the purchase of the Michelin Pilot Sport 4S rubber is pretty phenomenal. Switch into Drift Mode, go caveman with the throttle on a hairpin exit and it’ll have a shimmy, but as soon as the car detects corrective lock, it’ll scoot torque forwards. After a bit of experimentation, you realise that the key to prolonging the slide is both more throttle and, weirdly, winding on more steering lock.

If you grew up with hot Mitsubishi Evos or Subaru WRXs, there’s a lot about the A45 S that will spark déjà vu. We drove on one of the stages of Targa High Country and it would be hard to find a more perfect road for the AMG to show off its flea-like reflexes. Yet despite its effectiveness, there are some nagging doubts.

There are two main contributors to this slight equivocality. The first is the drive mode set-up. It’s an utter mess. Even now, after a week with the A45 S, the AMG Dynamics chassis system, with its various drive modes, three scalable dynamics interfaces, and separate controls for transmission, suspension, exhaust and engine maps seems anything but intuitive. You’re always beset by a concern that whatever setting you’re in, it’s likely you’re in the wrong one.

Viewed in terms of driver reward, the A45 S can’t quite level with these specialist coupes, but it’s worth noting that none of this illustrious trio will function as viable transport for rear-seat passengers with legs; none are as well-appointed as the A45 AMG, and none will have a hope of keeping up when the road gets wet. Perhaps we shouldn’t expect the Mercedes-AMG A45 S to be something it’s clearly not. Within the parameters set out for it, it’s a bloody marvel.

View our Mercedes-Benz models here:

Sourced: Which Car