BMW M4 vs Mercedes-Benz A45

What's the difference?

Brutal, bruising and utterly brilliant, the M4 CS will be an acquired taste due to its no-compromise approach, but those willing to take the leap will find a performance car like few others at their disposal.

The Mercedes-AMG A 45 4Matic+ may have grown up a bit in that it’s not as noisy or uncomfortable as the first-generation version which arrived in 2013, But if anything, its more portent than ever. Superb Mercedes-AMG craftmanship, outstanding performance and good value as far as bang for your buck goes.

The M4 CS is familiar in all the right ways, but definitely looks significantly jacked up compared to its lesser siblings.

Part of that is the extensive use of carbon everywhere, from its bonnet panels to its roof, front lip, side skirting and boot spoiler. But also because of its super-muscular angles and creases, including the huge dome in its bonnet.

Also exclusive to this M4 CS is the light treatment, with the front LEDs lighting up with yellow highlights the brand says are supposed to be reminiscent of GT racing cars.

At the back, the rear lights are flush with fibre optic lighting, lending a flowing and unique light signature that looks epic at night.

Inside, it's a sea of carbon, with the lightweight racing seats, the dash inserts and the centre console all lined in it. It is a perfectly finished space, though, and one that's also flecked with red, including a 12 o'clock band on the thick-rimmed steering wheel, the seat backs, the contrast stitching and the paddle shifts.

Be warned, though, it takes some acrobatics to climb into or out of the CS. The seat bottoms have these super high edges that double as grab handles, but require some awkward contortions to navigate.

In short, it looks angry, this M4 CS, inside and out.

When I went to pick up the Mercedes-AMG A 45 S 4Matic+ I walked right past it and then like that lost and confused John Travolta in Pulp Fiction internet memes, wandered around before asking where the car was.

That’s because I was looking for something with a gigantic spoiler on the roof and probably hi-vis green with stripes. But the car assigned to me was the A 45 S in its standard form, and the styling is subtle enough for it disappear into a crowded car park like James Bond into a lavish dinner party.

But like Bond, chances are the A 45 S is the most hardcore person in the room, it just doesn’t walk in announcing it to everybody.

Look closely and you'll see that the A 45 S is not just another small prestige car. There’s the 90mm quad exhaust poking out of the chunky diffuser, the giant 'Panamericana' grille, and the angry looking front apron.

Then, there are the 19-inch matt black alloy wheels wrapped in low-profile Michelin rubber and enormous brake discs with their red calipers, all barely contained by the pumped up front wheel guards which are much bigger than those on a regular A-Class.

The cost option my test car wore was the 'Mountain Grey Metallic' paint, but if anything it made the A 45 look even more covert.

The cabin is small but luxurious and sporty with two-tone leather upholstery (the red and black 'Lugano' leather in my test car is a no-cost option), there’s the microfibre-clad AMG steering wheel, brushed aluminium trim, metal-trimmed pedals and the large display panel (it’s actually two screens joined) is also standard.

The A 45 S is a hatchback measuring 4445mm in length, 1850mm wide and 1412mm tall. Not keen on a hatch but want something with similar dimensions? The CLA 45 S is the A 45 S’s four-door twin-under-the-skin and is just as much of a weapon.

And if you want your A 45 S to look more aggressive, you can option the 'AMG Aero Package' which will see a giant rear wing fitted to the roof.

Or you can buy the Edition 1 version of the A 45 S which includes the big spoiler and shouty design bits to makes sure everybody knows you’re the assassin in the room.

It all boils down to how you classify practicality in a car like this. I mean, the basic stuff is all there – it's got two doors, four seats and a boot capacity of 440 litres.

It measures 4801mm in length, 1918mm in width and 1399mm in height, and room for front seat riders is good, but less so for anyone you squeeze into the back. There are even ISOFIX points for a child seat.

But if you consider practicality the practical pursuit of performance, then the M4 CS has plenty of perks.

Along with good performance and handling, part of the appeal of hot hatches is that they’re practical… to a degree. The A 45 S is a small car, but it has four doors, five seats and a boot.

The cabin is small, no doubt about it, but even at 191cm tall I had plenty of room while driving, the seating position is perfect actually, although sitting behind my driving position saw my knees just touching the seat back.

Headroom is getting limited back there, but I still had space. Could you get away with the A 45 S as a family car? I had my family in it for a while, but there’s just the three of us and my son is pre-school-aged. So, a young, small family, yes… until it starts to grow.

Cabin storage is good with two cupholders in the rear centre fold-down armrest along with small door pockets and seat-back nets. Up front there are another two cupholders, giant door pockets, a big split-opening centre console bin and a tray for the wireless charger big enough to fit an iPhone 11 Pro Max.   

Boot space is good at 370 litres. The big shiny CarsGuide suitcase fitted in easily (see images) and apart from the wide-opening of the boot, another hatch power of practicality is that you can fold the rear seats down to open up more cargo carrying space, and in the A 45 S’s case that’s 1210 litres.

I’ve mentioned the wireless charger but there are also four USB-C ports (two up front and two in the rear), back seat passengers also have directional air vents, which is another bonus, along with dark tinted windows (welcome when my son was sitting back there in his car seat).

The new Mercedes-AMG A 45 S 4Matic+ lists for $93,600. Coming standard are the 19-inch matt black alloy wheels, the quad exhaust and chunky diffuser, Panamericana grille and AMG front apron, the red brake calipers, small roof-top spoiler and privacy rear glass.

Inside, the A45 S comes standard with sport seats and tone-tone leather upholstery – there’s ‘Yellow cut’ leather with contrasting yellow top stitching (or in the case of our car the no-cost option of red and black Lugano leather), and an AMG Performance steering wheel clad in 'Dinamica' microfibre.

Also standard is the large landscape display which is actually two 10.25-inch screens; one for the digital instrument cluster and another for the media system.

There’s also Apple CarPlay and Android Auto, sat nav, a Burmester stereo, 'Mercedes Me' (voice recognition) assistant, digital radio, wireless phone charging, power adjustable and heated front seats, dual-zone climate control, ambient lighting, proximity key, LED headlights and a panoramic sunroof.

The only feature I felt was missing was a head-up display, which needs to be optioned.

In the first year of sale (until the end of 2020) an Edition 1 version of the A 45 S will be sold. Listing for $101,690 the limited edition comes with a tougher look thanks to the addition of the AMG aero package which fits the giant rear wing, along with 19-inch twin-spoke matte black alloy wheels, door decals and AMG performance seats. Oh, and it only comes in 'Sun Yellow.'

Rivals to the Mercedes-AMG A 45 S 4Matic+ come in the form of Audi’s RS3 Avant, the BMW M2 or, and this may seem like an odd suggestion, the Tesla Model 3 hatch. The latter is a pure electric vehicle but has a 0-100km/h time of 3.4 seconds and an output of 335kW… just saying.

Sitting under the A 45 S 4Matic+ in the A-Class range is the A 35 4Matic for a list price of $69,300. The A35 doesn’t come with the big Panamericana grille and the 2.0-litre engine has a lower output but still packs an impressive 225kW/400Nm.

BMW has found yet more grunt lurking in its trusty 3.0-litre 'M TwinPower' six-cylinder petrol engine, with the M4 CS now pumping out 405kW and 650Nm.

That's a decent jump from the 390kW and 620Nm served up by the M4 Competition, and a giant leap from the outputs of the 'base' M4 – 353kW and 550Nm.

Predictably, then, the CS is the fastest of the lot, knocking off the run from 0-100km/h in 3.4 seconds, compared to 3.5 and 4.2 in the Competition and M4, respectively. The top speed is also dialled up to 302km/h.

All that power is channeled through an eight-speed automatic and sent to all four wheels on demand, with the help of an 'Active M Differential'.

There may be hot hatches out there which look wilder than the Mercedes-AMG A 45 S 4Matic+ but do they have the most powerful four-cylinder engine ever to go into a mass-produced car? Nope, but the A45 does: it’s a 310kW/500Nm turbo-petrol four.

It doesn’t sound as angry and gravelly as the previous A 45’s engine but it has more grunt (an extra 30kW/25Nm) and is claimed to catapult the hatch from 0-100km/h in 3.9 seconds.

The '4Matic' part of the name indicates the hatch is all-wheel drive and the '+' means it’s a more sophisticated version of the system which allows all of the drive to be sent to one axle, if need be.

What need would that be? The need to drift, of course, which should be up there with other human rights such as clean air, fresh water and free speech.

Yep, the A 45 S comes with 'Drift Mode' (for the racetrack, of course), along with a 'Launch Mode' for perfect-every-time transitions to warp speed.

Changing gears gunslinger-fast is an eight-speed dual-clutch automatic transmission.

The M4 CS is fitted with a 59-litre fuel tank, which – given the BMW's official fuel claim of 10.2 litres per hundred kilometres – should deliver a driving range on a full tank of 541 kilometres.

But... BMW also says the regular M4 – you know, the one that makes 52 fewer kilowatts and 55Nm less torque – uses 10.1L/100km, so do with that information what you will.

Mercedes-AMG says the 2.0-litre, turbo-petrol, four-cylinder in the A 45 S should use 8.9L/100km after a combination of open and urban driving.

My fuel test saw me drive 131km of urban and country roads, plus some motorway sections, and needed 16.9L of premium unleaded petrol to fill the 51-litre tank back to full.

That comes to 12.9L/100km, which is thirsty, but my driving style may have contributed significantly to that high figure.

The hardest and angriest M4 of all time is, perhaps unsurprisingly, hard and angry. This is a race track specialist, but because I don't happen to own one of those, my first experience with the barking (and barking mad) M4 CS was navigating my way back from BMW's inner-city dealership.

Like it or lump it, you're going to read some Porsche comparisons here, because you're talking not too far off base 911 Carrera money, and suddenly I find the two Germans doing battle for a spot in my dream garage.

First things first, the BMW won't be much chop for daily driving for most people. Happily, I have a sickness for uncomfortable sports cars. It tells me that no compromises have been made in the pursuit of punishing performance.

A good thing, too, because the BMW, at city speeds, can be punishing. Everything feels heavy, the seats aren't overly comfortable – especially the hard bits that tend to dig in when cornering – and it stiff-arms its way over road imperfections, that exhaust booming and barking as it does.

Again, I loved it, and you probably will, too. But it's still not the kind of car I'd relish sitting in the morning peak hour rush in.

But escape the confines of the city and the BMW M4 CS suddenly makes a whole heap of sense. The acceleration is genuinely brutal, and wonderfully theatrical, with that quad-tipped titanium exhaust barking and snarling as you rocket towards 100km/h.

The steering is brilliant, with feedback fed to your wrists via that thick-rimmed wheel, and the entire experience feels sharp, super engaging and edgy.

You can push the M4 hard and fast, and I'm certain my limited talents would run out far before the BMW's would, but there's this thrilling sense of peril sparked by the aggression of the experience, that I love.

It's like the magic of a roller-coaster, I guess. Even if you know nothing is going to happen, you never really know, right? And in that lies the magic.

But back to original question, this or a Porsche 911? There's no doubt a Carrera is a better all-rounder, in terms of comfy commuting and race track fun, but this angry M4 is all shouty theatrics, all of the time.

I bloody love it.

I wasn’t lying in the introduction to this review. The previous A45 was a pretty intense driving experience. The ride felt brutal, the exhaust note screamed and crackled like somebody had set a wheelie bin full of fireworks alight.

And then there was the sweating. I seemed to sweat a lot driving it and there was nothing wrong with the climate control, that just happens to me when I’m under pressure and excited.

So, has the new-generation A 45 S 4Matic+ gone all soft and quiet on us? No, but things have been toned down a tad.

The exhaust note is not as gruff or loud, and even in 'Sport +' and 'Race' mode it’s still quiet enough to pull into a driveway at night without making enemies of your neighbours.

And the ride is also not as harsh, although even in 'Comfort' mode my wife still found it verging on too firm.

The performance and dynamics, however, felt as sharp as ever.

Acceleration is supercar quick at 3.9 seconds. My gawd, you needed a Ferrari F40 to do that in the mid-’80s, and even now the new Mercedes-AMG GT S supercar gets there only a tenth of a second earlier, and it has a twin-turbo V8.

Top speed for the A 45 S is electronically limited to 270km/h. But hot hatches aren’t really about straight-line speed, they’re more about bent-line speed. You know, corners.

So, I took the A 45 S on the twisty roads I take anything that calls itself sporty. The agility of the A 45 S is outstanding thanks to a rigid chassis that handles a change in direction as quickly and easily as you can turn your head.

The brakes bite hard when they have to, and the all-wheel drive hatch scrambles tenaciously out of corners.

A racetrack is really the best place to truly test a serious sports car's limits and our own James Cleary did just that when he drove the A 45 S at its international launch.

As a daily driver, though, for somebody who occasionally likes to get into it on a curvy road the A 45 S is comfortable enough to live with, but hard enough to remain engaging and dynamic when you get the chance to have a squirt.

The Mercedes-AMG A 45 S 4Matic+ received the maximum five-star score when it was tested by ANCAP in 2018.

The safety equipment list is impressive. Along with nine airbags and a 360-degree camera there’s advanced safety tech such as AEB with cross traffic function, blind spot warning, lane keeping assistance, lane change assistance, auto parking and adaptive cruise control.

For child seats there are three top tether points and two ISOFIX mounts across the second row. Small hatches are the easiest cars to put top tether seats in thanks to the good access to the hook point. I fitted my son’s car seat into the back of the A45 S without any problems.

The M4 CS is covered by BMW's five-year, unlimited-kilometre warranty, with condition-based servicing available in packs, which will cost you $3530 over five years/80,000km, or $2900 over four years/60,000km.

The Mercedes-AMG A 45 S 4Matic+ is covered by a five-year/unlimited kilometre warranty.

Servicing is recommended at 12 month/20,000km intervals. Servicing is capped at $850 for the first year’s visit, $1200 for the next and $1600 for the third.