3.9 out of 5 3.9
Parkers overall rating: 3.9 out of 5 3.9

The world's most powerful four-cylinder production car

Mercedes-AMG A 45 Hatchback (19 on) - rated 3.9 out of 5
Enlarge 40 photos

At a glance

New price £50,595 - £56,595
Lease from new From £527 p/m View lease deals
Used price £35,630 - £47,515
Used monthly cost From £889 per month
Fuel Economy 31.4 - 32.5 mpg
Road tax cost £475
Insurance group 40 - 41 How much is it to insure?
New

PROS

  • Plenty of grip on offer
  • Explosive performance from 2.0-litre engine
  • All-weather usability
  • Hard to keep up with on the road

CONS

  • Won't sound as exciting as rivals
  • Infotainment system not that intuitive
  • Ride will be firm compared with rivals
  • Hard to differentiate from A 35

Mercedes-AMG A 45 Hatchback rivals

Written by Lawrence Cheung on

With the £35,000 Mercedes-AMG A 35 already squaring up to the likes of Honda's manic Civic Type R and the lovely Volkswagen Golf R, this A 45 S has a starting price tag of just over £50,000, putting it toe-to-toe with pricier offerings such as the covetable Audi RS 3 Sportback and BMW's entertaining M2 Competition.

Bar the front grille, five-spoke alloy wheels and red brake callipers, you'd be hard pressed to tell the difference between the A35 and A 45 S externally - you'll have to opt for the Plus model to get the bodykit, rear wing and forged multispokes wheels.

Climb into the cabin and there are even fewer clues, because almost all of the extra £15,000 has been spent on either magnificent mechanical wizardry or sock-it-to-me software add-ons to the infotainment system.

The former includes the world's most powerful turbocharged four-cylinder petrol engine in series production, and a sophisticated rear differential that extracts even greater levels of traction from the all-wheel drive system.

The latter appears to take the form of a demonstration by Mercedes' software boffins that throwing in the metaphorical kitchen sink is really no more than a starting point in relation to what's achievable with an already excellent infotainment system, and too much time on your hands...

Subtle interior differences for A 45 S

A relatively low-key upgrade to the standard A-Class interior rewards the A 45 S with sportier seats, attendant go-faster stitching with matching yellow highlights dotted around the cabin, twin 10.25-inch screens perched on the dashboard in lieu of a proper driver's instrument binnacle, and a scattering of AMG badging.

They've not only sliced the bottom off the steering wheel, but the Alcantara-wrapped sides too, bringing your arms ever-so-slightly closer together and your fingers in easy grasp of the small paddles. The addition of the rotary drive mode selector and buttons for the exhaust and transmission modes make it far less of a faff to adjust than fumbling around the centre console to press the duplicate switchgear.

The materials used in the cabin are certainly better than its predecessor, but it remains a little creaky in here, so only time will tell when the firm suspension starts to shake the odd bit of trim loose.

The diminutive thumb-operated track-pad type controls mounted on the steering wheel will prove vexing for those brought up on a diet of Mercedes' more tactile, accurate and intuitive roller switches, while the absence of a proper switch to instantly disengage the ghastly lane keeping assist without wading through menus is a disaster.

Shame, really, that a fine infotainment system with terrific graphics - clearly visible even in bright sunlight - should become so over-planted with because-we-can superfluous software trees as to often make the wood nigh-on invisible.

The centrally-mounted sensor pad is haptic, but you have no idea where the cursor is at any point, as the highlighting is so poor, so it takes ages for your eyes to identify where you are on the screen and which icon is selected. If it's infuritating enough for the front passenger to use, it’s bad news for the driver on the move.

Of course, you could resort to using the Hey Mercedes voice control for some of the functions, but it's so sensitive it'll mistakenly activate, stop the music and ask what you want when you are simply mid-conversation with a passenger. It's like you have to try and talk without waking up a sleeping toddler.

Comfort - a little less annoying than the A 35, but acceptable for £50k?

The AMG suspension predictably toughens up as you dial up the sportier settings in the selection of drive modes, with potholes sending large thumps into the cabin. Those of a loose-fillinged disposition may wish to opt for the B road safety of Comfort mode, which does at least offer a modicum of pliancy and avoids being too jittery at higher speeds.

There's plenty of road noise generated by those ultra low-profile 19-inch tyres, too, while the front seats initially feel about as forgiving as those sidewalls as well.

In a performance hatchback like this, it's hardly surprising. Curiously, the compromise on comfort feels a little more acceptable in the A45 S when this level of performance is on offer, whereas in the A 35, it just feels annoying. With the latter, you just got a really uncomfortable hatch offering the same level of power as a VW Golf R or Audi S3 for no discernible gain. The A45 S at least feels more purposeful, but is it acceptable in a £50k car? Not many would think so...

There have been gripes about the setting of the AMG A 35's driver's seat too high, but the A 45 S seems to suffer from no such problem. The sports seat is snug and comfortable enough, with excellent lateral support, though it would be good if the steering wheel adjustment allowed the helm to be lowered a little more.

There is, alas, no Jesus handle atop the door frame for the front passenger to cling onto when lateral G rises, and the rear seat passengers, though they won't lack for either head or legroom, must suffer the same misfortune exacerbated by far less lateral bolstering to their seats. Given this car's cornering abilities, this seems an odd oversight.

One engine choice

No engine choice here; just the one. Not only does it set new benchmarks for four-cylinder performance, it's an absolute gem, with 420hp and 500Nm of torque meticulously extracted from this hand-built 2.0 litre unit.

Unlike most turbocharged engines of this size, it'll eagerly rev to 7,000rpm and haul this hatchback beyond any intended speed limit without a second thought. Whether it's a 30- or 50mph zone, it'll get you there with so little ease that you'll have to keep your eyes on the speedometer with heavy concentration, which also speaks volumes about the stability on offer, given the lack of sensation of speed.

Mated to an eight-speed dual-clutch transmission with paddle shift override and all-wheel drive, this glorious sounding powerplant will shove the A 45 S to 62mph from a standstill in just 3.9 seconds and on to a top speed of 168mph.

Some of the engine noise is artificially piped into the cabin, but you do get the loud exhaust to accompany it with pops and bangs whenever you lift off the accelerator pedal or change gear. It's not over-the-top, and it only switches on in Sport+ and Race drive modes only - at which point you can specifically switch if back off anyway.

You won't come across much of that torque below 3,000rpm no matter which of the seven available drive modes you select (and all you really need is a choice of Comfort or Sport+), but thereafter - with all the theatrical noises you'd expect from such a highly-tuned unit - the hatchback takes off like a stabbed rat in any of the eight gears except the last: dropping out under the pressure of even a gentle motorway incline, eighth is really just a fuel-saving cruising gear.

The gearchange is wonderfully quick and smooth either left to its own devices or dictated to by the steering wheel-mounted paddles, and you'll have to be approaching the rev limiter in any gear to elicit even the slightest hiccup in proceedings.

It's quite slow on downshifts though, so the initial pause can have you pulling the left paddle one too many times when you think it hasn’t registered your inputs - leaving you one gear too low and bashing into the rev limiter. This could be better calibrated, but it's otherwise a very good transmission.

AMG A 45 S turns up the wick

But what really sets the A 45 S apart isn't just the superb powerplant, but the extent to which you can deploy all that power courtesy of Mercedes' 4Matc+ rear differential, which houses a multidisc clutch adjacent to each wheel.

This allows the system to not only apportion drive between the front and rear axles - from 100% rear to 50/50 front and rear - but also up to 100% between the rear wheels.

And that equates to ridiculous cornering prowess. Inner rear wheel braking helps minimise understeer on the way in, and perfectly judged torque distribution allows you to get back on the throttle hilariously early on the way out, leaning on that outer rear tyre as hard as you like without so much as a squeak of oversteer.

Though far from the last word in communication, the steering has a respectable heft to it, especially in Sport+ mode, but the weighting seems to be one-dimentional. It remains ruthlessly accurate at all times, however, even if you’ll have little idea of how the front wheels are coping in terms of grip. Traction levels remain high at all times and the brakes are fantastic at shedding speed and disguising the 1,635kg weight.

Running costs

During our time of testing, we saw the A45 S achieve between 34-36mpg when sat on a motorway cruise, but this dropped very quickly to the high 20s once off it. This lines up with the official combined figures of 31-31.4mpg.  When it comes to CO2 emissions, this 2.0-litre engine pumps out between 204-207g/km depending on model.

Mercedes-AMG A 45 Hatchback rivals