How Mercedes-AMG fixed the A45 S

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

2020 Mercedes-AMG A45 S

Overall Rating

5 0 5

Plus & Minus

  1. Plus Phenomenal powerplant; sheer cross-country pace; talented chassis; plush interior; clever engineering

  2. Minus Getting expensive; drive modes confusing; voice recognition flaky

The Wheels Verdict: If you expected this new Mercedes-AMG A45 S to be more of the same, think again. It’s a 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.

2020 Mercedes-AMG A45 S

What is the Mercedes-AMG A45 S?

Back in 2013, AMG revolutionised the fast hatchback market with its A45. That car was raw, edgy and uncouth but gave a tantalising taste of 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 and it’s yours for less than $100K.

Why we’re testing it

Our curiosity had been piqued by glowing reviews of the A45 S from its international launch and this was the first chance we had to drive it on Aussie roads. With that in mind, we took it to one of the very toughest we knew, the queen stage of Targa High Country between Eildon and Jamieson, in Victoria’s high country.  If the A45 S could shine there, it could shine anywhere.

2020 Mercedes-AMG A45 S


I know you’re busy, so let’s cut to the chase. AMG needed to fix three things to turn the old A45 into the best hyper hatch in its division. It needed to ride better, it needed a smarter gearbox and it needed to be more involving for the keen driver. Those requirements have been addressed with the all-new Mercedes-AMG A45 S. So that answers how Mercedes ‘fixed’ the A45.

Since you’re here anyway, you might well want to discover how AMG went about each of those three remedial measures, but first a bit of background to get you fully up to speed. The old A45 AMG debuted in 2013 with 265kW/450Nm and was revised in 2016, bringing adaptive dampers and an uptick in grunt to 280kW/475Nm. Still the same turbo 2.0-litre engine driving all four wheels, still the quickest car in its class at 4.2 seconds to 100km/h.

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.

But the A45 really didn’t need to be any quicker, any louder or any glitzier than before. While it was long on headline-grabbing numbers it was, to summarise its faults, short on subtlety. There are some cars that really shine when pushed hard. The A45 wasn’t one of them. Up to about eight-tenths it felt rock star. Ask any more of it and you began to suspect it was one of those rock stars who only know a couple of chords.

In order to extend the repertoire 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.

2020 Mercedes-AMG A45 S

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.

2020 Mercedes-AMG A45 S

Go too hard into a corner in the old A45 and it would doggedly understeer, and it seemed virtually immune to any of the strategies that a good driver would normally use to bring understeer back to neutrality without completely killing off all forward velocity. In certain regards it felt like the days of old AMG when you got a fantastic engine mated to a chassis that seemed to account for the remaining 10 percent of the vehicle development budget. That has certainly changed for the better, but is it all the way there? That’s a tough one.

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 percent of the torque directed rearwards to be sent to either side. The issue some will have is that 100 percent in this instance isn’t actually 100 percent of the total torque. In typical driving, the A45 S will send a maximum of 50 percent of drive backwards. The much-vaunted drift mode doesn’t disengage the front driveshafts and turn your A45 into a rear-driven monster. Instead, it works by the simple expedient of overspeeding the rear axle in relation to the front. It still doesn’t send more than 50 percent rearwards. It just sends all of that 50 percent to the outside rear wheel.

Drive the A45 S hard on a challenging road and it’s clear that AMG has got an awful 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 calipers. Body control is tight, front-end grip imperious and turn-in tenacious.

2020 Mercedes-AMG A45 S

The engine’s 250rpm-wide torque maximum sounds peaky, but in reality there’s so much at your elbow that anything above 3000rpm will do. By 4000rpm you’re really moving, and above 5000rpm, the car’s persona transforms, a barrel-chested roar filling the cabin that sounds as if it can’t possibly come from 1991cc of swept capacity. Mercedes Australia confirmed that none of the A45s on their press fleet are fitted with the optional sound symposer. Crikey.

That the engine punches well above its 160.5kg weight is clear. Moers again: “The reason [it makes so much power] 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.

2020 Mercedes-AMG A45 S

Up the pace, and things get far 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.

2020 Mercedes-AMG A45 S

Then there’s pricing. Okay, it sounds churlish to quibble with what Mercedes-AMG is offering for less than $100K, but bear with me on this one. You’ll need to dig up $93,600 for the admittedly well-equipped A45 S, a hike of around $15,000 compared to its predecessor. This Edition 1 special retail with its outré cosmetics retails at $101,690 before on-roads and options, and what you get is a far better car than the old A45. The issue now is that the price increase brings it within striking range of models like the $99,900 BMW M2 Competition Pure and the $97,000 Alpine A110 Pure. Come to think of it, let’s throw the $116,000 Porsche 718 Cayman into the mix as a stretch target.

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.


Audi RS3, BMW M2

2020 Mercedes-AMG A45 S

Mercedes-AMG A45 Specs

Model: Mercedes-AMG A45 S

Engine: 1991cc 4cyl, dohc, 16v, turbo

Max power: 310kW @ 6750rpm

Max torque: 500Nm @ 5000-5250rpm

Transmission: 8-speed dual-clutch

Weight: 1625kg

0-100km/h: 3.9sec (claimed)

Economy: 8.3L/100km

Price: $93,600 ($101,690 Edition 1)

On sale: Now


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