Mercedes-AMG A 45 S 4MATIC+ 2020 Review

To sum-up the Mercedes-AMG A 45 S, I’ll quote my favourite comedy duo Hale & Pace in a skit referencing Jeremy Clarkson – “it has more knobs than Royal Ascot”.

This German hyper-hatch is just packed with every conceivable bit of equipment that can be jammed into a small five-door and AMG doesn’t miss you on the price either – it will set you back a cool $93,600 plus on-roads.

That makes it almost 20K pricier than its predecessor, but in terms of bang for your bucks it’s probably worth it.

The mechanicals get the biggest makeover with a heavily revised rear-biased all-wheel drive system incorporating ‘drift mode’, and an all-new engine that produces record-breaking power.

Exhibiting a little more restraint in its exterior styling than the outgoing model, the new A 45 S still hints at its menacing performance with 19-inch wheels over massive 360mm front and 330mm rear rotors, a bold Panamericana grille, wider guards, thicker side skirts and smallish rear spoiler with a pair of 90mm exhaust outlets set in a discrete rear diffuser.

The interior is dominated by a pair of 10.25-inch screens controlled by the MBUX infotainment system and, much to my two daughter’s delight, 64-colour ambient interior lighting that could put most discos to shame!

Heated front seats, tinted windows, keyless entry, sunroof, a Burmester audio system and dual-zone climate control complete the standard features.

When you first get behind the wheel of the A45 S all the bells and whistles in front of you can seem a little overwhelming, but once you’ve lived with it for a few days all the features are intuitive and easy to manage.

There’s one thing Merc can never be accused of and that’s a lack of safety tech, driver assistance tech or just plain tech.

The Mercedes-AMG A 45 S is no exception and it has the aforementioned in spades and then some. Features like LED headlights with auto high-beam, adaptive cruise control, autonomous emergency braking, lane-change assist and blind-spot monitoring headline the safety tech.

But there are so many other functions available I reckon I’d never get through them I played with one a day for the next decade! For example, I was an hour into a road drive when the screen suddenly asked me “would you like to be revitalised?”

Interesting, I thought to myself, so I said ‘yes, yes I would’… at which point the audio suddenly switched to a ‘revitalising’ song, the seat proceeded to massage me, the lighting changed and the climate control system wafted an intermittent ‘sea-breeze’ every 10 seconds. Wow, that’s cool.

Got young kids? They’ll be entertained by the over-the-top light show in the cabin, and have hours of fun taunting the voice-activated control that learns your voice. And there’s a heap of USB ports but annoyingly every single one is the ‘C’ type – not the conventional ‘A’ type – and it doesn’t come with adaptors.

I’ll take AMG’s word that Apple CarPlay and Android Auto are on board, but the wireless charging was a Godsend since I couldn’t actually plug my phone in!

Mercedes-Benz definitely knows how to do engines and the A 45 S puts out a staggering 310kW of power and 500Nm of torque from its 2.0-litre four-cylinder turbo-petrol powerplant – up 30kW and 25Nm over the previous generation.

It is in fact a completely new engine dubbed M139. The boffins at AMG have turned the cylinder-head 180 degrees so the turbo is now positioned up against the firewall, enabling more efficient exhaust and inlet piping which increases response.

The redline has increased by 500rpm to 7200rpm, with peak power now at 6750rpm – 50rpm over the previous engine’s actual rpm limit – and max torque at 5000rpm.

That may sound a little high but it produces a stump-pulling 440Nm from as little as 2000rpm, with a steady climb from there. These incredible figures make it the most world’s powerful four-cylinder production engine.

It’s fair to say the Mercedes-AMG A 45 S doesn’t need that much power and you can bet your bottom dollar this engine will appear in other AMG applications.

Transferring all that grunt to the pavement is a dynamic all-wheel drive system and an eight-speed dual-clutch transmission that can see 0-100km/h disappear in 3.9 seconds and an electronic limited top-speed of 270km/h.

AMG’s Torque Control system is the major influence on the feel and balance of the Mercedes-AMG A 45 S (read on to see whether it can actually back up its claims) and it does this by distributing torque between the front and rear axles and even independently across the rear.

Statically, torque split is 50:50 and the system can never actually apply more torque than that to the rear, but it can apply 100 per cent of that torque to the outside rear tyre in the case of drift mode, for example.

As an everyday driver, the Mercedes-AMG A 45 S has the mix spot-on. I would even class it as a family car (it does have five doors and five seats after all) as I could easily accommodate the kids’ car seats in the back plus a heap of luggage in the 370-litre boot.

Functionality is probably the word I’m looking for and it has and does everything one would expect from a ‘conventional’ family hatch.

The neighbours will appreciate the toned-down exhaust note, which for us racers is an unfortunate by-product of European noise regulations but still offers subtle hints of the fire-breathing heart under the bonnet.

Ergonomics are good and steering feel and weight are very good, as is the brake pedal feel. Ride quality is comfortable and overall poise much improved over the outgoing model.

But switch to ‘race’ mode and the animal in it suddenly comes alive, sharpening the suspension, optimising the response rate of all driving functions and making for a somewhat formidable track-day sleeper.

Speaking of racetracks… you know me and I couldn’t not take it for blast around one, could I? To save the tyres I literally only did one hard lap (honest, Mercedes-Benz Australia!) around my home test track – Norwell Motorplex – where carsales and I last tested the A 45 back in 2016.

The best lap time then was a 64.52. Four years on and the new A 45 S clocked a 61.91 second lap! There was a little more left on the table there too as it was a messy lap, but it demonstrates how much the A45 has improved in only a short time.

There’s no question the Mercedes-AMG A45 S is very fast and an amazing bit of kit. The engine is phenomenally powerful for such a small-capacity unit and warrants an equally good chassis – which is where it unfortunately falls just shy of the mark.

The new AWD system with its ‘rear-drive emphasis’ sounds great on paper but on track seems very confused. I cut all my laps in every car with the ESC off to highlight the vehicle’s raw chassis dynamics, and I strongly advise that you better know what you’re doing before thinking about touching that button in the A 45.

I don’t think I’ve ever sawn at the wheel in any car as much as I did in this one. It feels like the car is saying to itself “OK, I’m understeering, so let’s apply torque to the rear … oops, that’s too much, lets back it off … no, not that much, lets go more to the rear again”.

All the while the driver is applying opposite lock then straightening, more opposite lock then straightening. It’s hard work and I’ve got the on-board footage to prove it. Bear in mind this is while pushing it hard – go at eight-tenths or for a spirited road drive and it’s brilliant.

I think a better tyre like a Michelin Pilot Sport Cup 2 as opposed to the Michelin Pilot Sport 4 S rubber fitted to our test car would go long way in helping its on-track demeanour because, as it sits, the Mercedes-AMG A 45 S is an engine looking for a chassis.

If the track is not for you and spirited road driving is more your thing, then this is arguably as good as a hyper-hatch can get. But on track, you’ll need your wits about you and you’ll actually have to ‘drive’ this car.

Which suits me just fine but may not be everyone’s cup of tea.

How much does the 2020 Mercedes AMG A45 S cost?
Price: $93,600 (plus on-road costs)
Available: Now
Engine: 2.0-litre four-cylinder turbo-petrol
Output: 310kW/500Nm
Transmission: Eight-speed dual-clutch automatic
Fuel: 8.4L/100km (ADR Combined)
CO2: 192g/km (ADR Combined)
Safety rating: Five-star (ANCAP 2018)