BMW M Models vs Mercedes-Benz A45

What's the difference?

Let’s get one thing out of the way: the new M5 is a very good car. Considering the emissions limitations and size increase of its base model, it is an impressive bit of engineering. 

What’s trickier is deciding whether the new car is really better to drive. Less edgy but supremely comfortable and quiet; BMW leaned into the daily usability of the plug-in hybrid M5 rather than amping the petrol-electric system for maximum thrills. And do you know what? That’s fine with me. 

The new M5 still performs on road and track and does an incredible job of hiding its weight (most of the time). Perhaps the G90 is a little more Audi RS6 than F90 in its demeanour but some would argue that’s no bad thing. 

The concept of the BMW M5 is not static, it evolves with the times, and the G90 is no exception. Expect future Competition and CS variants to unlock some extra lunacy. 

Note: CarsGuide attended this event as a guest of the manufacturer, with meals provided.

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 M5’s raw size is what you notice first. The G90 M5 is a whopping 113mm longer, 67mm wider and 37mm taller than the car it replaces, with the wheelbase stretched 24mm.

It is also the most pumped M5 yet, compared to a 520i it is 70mm chubbier at its flared wheel arches. The ‘M5’ insignia on the C-pillar means you’ll know this is the fast one. 

Presence is not in question, then, but beauty? Not the right word. The G90 makes its predecessors — especially the original ‘E28’ — look demure. 

The cabin layout builds on the concept debuted by the iX electric SUV, with twin integrated screens and focus on technology and minimal buttons. Materials are mostly high quality and feel fitting for the M5’s asking price.

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.

BMW has persevered with its twin-screen, minimal-button approach for its 'Operating System 8.5' in the M5. 

The 14.9-inch central touchscreen is bright, responsive and high resolution but the software remains a little strange. The main interface is classy but when looking for settings to adjust you’re presented with a Windows 95-esque panel of small square touch targets. It’s not intuitive. 

Wirelessly mirroring Apple CarPlay or Android Auto works a treat, at least. Digital climate controls keep temp adjustment persistently on screen and a shortcut to fan speed. The nipple-like vent direction adjustment grows on you, as do the digital vent sliders. 

The 12.3-inch digital driver’s display still doesn’t have the freedom of customisation and clarity of Audi’s interface. 

The M5 has two cupholders, a deep central storage cubby, door bins that swallow two 600mL plastic bottles and twin wireless charging pad that resolutely grips smartphones even under the sort of tummy-churning G-Forces this M5 can manage. 

Setting the M5 apart from the regular sedan is a unique centre console bunching 'M Drive' modes, 'M Hybrid' modes and other shortcut functions together next to the gear toggle and M-engraved crystal 'iDrive' controller.

Comfortable front seats are power adjustable with in/out, up/down lumbar support and have two memory positions. 

The 5096mm long M5’s back seat is very spacious. Headroom is good for those beyond 182cm (six-foot), the bench is extremely supportive, while leg and toe room are adequate.

A fold-down centre armrest has two cupholders and there are USB-C charge ports in the back of each bucket seat for a total of four. 

You can buy an accessory mount that holds tablets or smartphones for rear seat passenger entertainment, too.

When you look in the boot, BMW offering a Touring version of the latest M5 makes even more sense. The load aperture is big but the usable space is narrow; the sides intrude on load space. 

The 466-litre space will make fitting suitcases for an airport run tricky and, even with the 40/60 split-fold rear bench, you will struggle to fit a bike in the back. There’s no spare tyre, either.

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.

Unlike the Mercedes-AMG C63, BMW has kept the M5’s eight-cylinder heart and this has proven to be a good decision. 

The 4.4-litre twin-turbo petrol engine has been optimised with “a cross-bank exhaust manifold and optimised oil separation”, says BMW.

The V8 spins to 7200rpm though it isn't a screamer, outputting a full-bodied 430kW (5600-6500rpm) and 750Nm (1800-5400rpm).

Augmented with a transmission-mounted 145kW electric motor that can produce up to 450Nm, thanks to pre-gearing, maximum combined outputs are 535kW and 1000Nm. 

Weight blunts punch, though, so despite nearly 100kW and 250Nm more, the new M5 is a tenth slower to 100km/h than its predecessor (claimed), at 3.5 seconds for the sprint.

You can thank a 220kW/tonne power-to-weight ratio, worse than the old car's 233kW/tonne figure. The new G90 claws some time back with brute force, hitting 200km/h in just 10.9 seconds and goes on to a limited top speed of 305km/h.

You can choose from five powertrain settings, starting with 'Electric' and 'Hybrid' for everyday use, while 'eControl' lets you store battery power for urban use.

'Dynamic' provides the best balance, says BMW, while 'Dynamic Plus' is like a qualifying mode. Think maximum combined punch for up to 10 minutes, at which point you’ll have drained the battery. 

Driving in pure electric mode, the take-off can be a little jerky but the quietude and decent power make it pleasant. Power sources are combined expertly in Hybrid and giving it some stick in Dynamic is more than enough to make your passengers feel queasy.

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.

Electric-only range is rated up to 69km in WLTP testing, but the 18.6kWh battery is more likely to give you around 60km in real-world driving. It can be topped up in about two hours using an 11kW AC charger, or overnight on a three-pin socket. 

BMW includes both Mode 3 (public) and Mode 2 (home) charging cables with the M5. 

The M5 uses 3.2L/100km of 98 RON premium unleaded in ADR testing, corresponding to just 72g/km of CO2, so it should sail through the first rounds of Australian emissions regulations. 

Indulging in what the V8 has to offer sees that consumption spike, though. An enthusiastic road drive saw the M5 gulp 12.4L/100km, according to the trip computer.

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 three M5 elements start with daily usability. We trundled out of Bathurst in electric mode, with the adaptive dampers (and other myriad settings) in Comfort. 

The M5 has steel springs, double wishbone front suspension and a five-link rear axle, all of which has been heavily reworked by the boffins at M. Naturally, the ride is firm, though in Comfort the body moves through its motions smoothly. 

The M5 is an effortless tourer, its eight-speed automatic shmoozing through ratios as it climbs and descends steep gradients. Wind and tyre noise insulation is good on coarse chip tarmac, though a bit more burble from the V8 would be appreciated. 

The M5 has nine adjustable parameters to wake it up: 'Drivetrain', 'Energy Recovery', 'Drivelogic' (gear shift aggression), 'Chassis', 'Steering', 'Brake', 'M xDrive', stability control settings and 'M Sound'. Favourite settings can be stored to the wheel-mounted M1 and M2 buttons. 

With the dampers still in Comfort the M5 remains fantastically capable with power delivery from the xDrive mighty rewarding on corner exit. Sport dampers sharpen the experience up further, amplifying the M5’s surprising agility. Thank the rear-wheel steer for this big sedan’s switchback performance. 

Step beyond the limit of grip, brake too late, or get on the power too early, though, and the M5’s mass reveals itself rapidly. It doesn’t help that the accurate steering is devoid of feel. The brake-by-wire pedal is too numb and light, as well, making it tricky to judge grip levels on the road.

Feel is less of an issue on a dry Mount Panorama circuit, where the M5 turns out to be a total pussycat. The all-wheel drive, consistent dynamics, strong brakes and well-tuned stability control make for an approachable but seriously fast sedan.

The responsive transmission will hold gears to redline and is eager on the downshift in its most aggressive setting while tactile shift paddles make commanding ratio changes yourself that bit more engaging. 

Prodigious punch out of corners is matched by the impressive consistency of the carbon ceramic brakes. The M5 pulled up for The Chase every time with minimal fuss, even from above 250km/h.

Similar credit goes to the 285mm front and 295mm rear Hankook S1 Evo tyres which remained consistent and predictable all day despite reaching temperatures over 130 degrees, according to the tyre pressure monitor.

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.

In Australia, BMW has moved to match other manufacturers in offering a five-year/unlimited kilometre warranty on all its cars. 

Servicing is recommended on a condition basis, with the M5’s multimedia system prompting a visit to the mechanics. BMW offers pre-paid service packs for five years/80,000km at a price of $5059 for the basic offer and $8152 for 'Inclusive Plus', which covers brake pad and rotor replacements. 

It is expensive next to a regular 5 Series but when you consider the purchase price and performance level, the M5’s service pricing is not astronomical. 

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.