Audi S5 vs Mercedes-Benz A45

What's the difference?

The Audi A5 remains a convincing option in the premium mid-size sedan category, even with the near-$10K price increase over its equivalent grade A4 predecessor.

Even in its base spec, it’s a lovely thing to drive and adds enough new kit to be a reasonable option when it comes to value. In terms of tech usability, it stands out from rivals. Practicality is still king for Audi.

But for the heart-over-head types, the S5 is fast and fun while remaining a comfortable cruiser and the price is decent. On a personal note, a six-cylinder wagon? That's a big yes from me.

For the time it’s available, it’s hard to go past the value on offer in the S5 Edition One. Getting an AWD V6 with that kind of capability for under $100K is something that's sure to tempt buyers. If it doesn’t, we need to take a good look at ourselves.

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 A5 incorporates Audi’s new design language in a way that makes the 2026 model stand out from Audi’s older offerings, but we won’t know how well it works in the family until more new-gen Audi cars arrive.

For now, the A5 is a generally handsome car. It very much looks like an Audi from the front, even a recent A4 if you only very quickly glanced.

The aforementioned S line styling does plenty in making even the base Audi A5 look like a properly luxe thing. There were a few double-checks at the launch to make sure drivers were getting into the right cars.

Fortunately the new car’s designers refrained from busying up the car with trim, the only big features being the side vents at the front.

But even in Avant form the S5 looks athletic, quad-exhausts in the lower bar and the angular rear bodywork moving away from the previously softer, more rounded look Audi had gone with before.

Inside, the changes are arguably more obvious. The A5 is now much more ‘screeny’ than before, especially if optioned with the passenger-side touchscreen.

It’s still decidedly Audi in its layout and design, with geometric shapes on the steering wheel, screen housing, door cards and even on the gear shifter, which is no longer the more traditional handle-type.

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.

…and that gear selector is a bit indicative of the new A5’s interior. It’s now more of a switch that requires a little more attention than the traditional shifter, just like the way the more screen-focused interior requires a little more of your eyeball time than physical buttons.

Don’t get me wrong, as far as screens in modern cars go, Audi seems to have made it as easy as possible to use the new-gen software in the A5. The menus are clear, there are good shortcuts and there’s no lag… but buttons are always better when your focus needs to be on the road.

Fortunately the driver display is nice and clear, it’s a good update on Audi’s ‘Virtual Cockpit’ and you can set it to display important information without looking too busy.

Ergonomically, the way the central screen is angled towards the driver, the centre console layout and the small control panel on the door for lights, mirrors and the like all seem to be well considered and mean you don’t have to awkwardly reach for anything.

There are a few quirks specific to the A5 and S5, one being that if you opt for the panoramic sunroof, it comes with a transparency switch rather than a physical cover, so it doesn’t do much to keep the light out.

It’s also good to note that the passenger screen - again, if optioned - turns to privacy mode when playing media so as to not distract the driver. Pretty handy!

Behind the front row, a regular-sized adult should have enough room to sit comfortably for a decent amount of time without feeling cramped. The light through the sunroof comes in handy here.

Behind that is a 445L boot in Sedan form, or 1299L with the rear seats folded down. As an Avant, the space increases to 448L and 1396L respectively.

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.

The Audi A5 is powered by a four-cylinder turbo-petrol engine which powers the front wheels via a seven-speed dual-clutch automatic transmission. It makes 150kW of power and 340Nm of torque, and should, Audi says, propel the A5 to 100km/h in 7.8 seconds before (eventually) reaching a top speed of 248km/h.

The S5, in all its variants, is powered by a 3.0-litre turbo-petrol V6 which is assisted by a mild hybrid system. It produces 270kW and 550Nm, sending that to all four wheels via a similar seven-speed dual-clutch.

The S5 is much quicker as a result - 100km/h comes along in just 4.5 seconds according to Audi, before reaching a 250km/h top speed.

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.

Audi claims the A5 uses 6.9 litres of fuel per 100km, which should theoretically deplete the 56-litre fuel tank after 811km of driving. We couldn’t test this on the launch, but reaching claimed fuel efficiency figures remains an elusive challenge.

The S5, according to Audi, comes with an impressive 7.1L/100km figure in Sedan form, or 7.2L/100km as an Avant. That’s 788km and 777km of theoretical driving range if you’re up for a challenge.

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.

One of the first press cars I ever drove as an even younger lad than I am now was the circa-2017 Audi S4.

Without the perspective of all the many, many cars I've since driven, that S4 blew my mind a little bit with its combination of capability and refinement.

Now, with the context of most of the cars available to the Australian buyer in mind, it’s reassuring to get into this new generation and find that the mid-size Audi torch has been gracefully passed on.

Audi says the new generation, sitting on its new platform, has more focus on balanced driving dynamics, steering precision and steering feel. Without sacrificing comfort, Audi wants the A5 to be a sharper driver’s car.

It might not gel with the Euro tradition of a rear-drive executive sedan given the base A5 is front-wheel drive - the brand of course focusing on its quattro all-wheel drive system - but the A5 is decidedly agile for its size. 

Compared to the S5 especially, as the A5’S 1770kg plays the S5’s 2025kg in Sedan form (2040kg as an Avant). It’s a noticeable weight difference, and it makes the A5 more playful without getting properly ragged.

It also rides on smaller 19-inch wheels and would overall probably make for the better daily driver. Even without the all-wheel-drive traction and extra power the S5 offers, the A5 makes a good case for properly plush commuting. Its 150kW isn’t lacking by any means, and that 340Nm does plenty to help when overtaking.

Its suspension feels well damped, keeping the road’s imperfections out of the cabin without numbing the ride and leaving you without feedback. The steering is similarly direct without being too heavy, making the A5 feel athletic for its size.

But for all the A5’s strengths, there is something undeniable about a six-cylinder European sedan (or wagon). The S5 is heavier, sure, and therefore not as naturally nimble, but it makes up for it. And it’s not just the extra power and mild-hybrid assistance.

It’s a great highway cruiser for a start, but it also adds the confidence of all-wheel drive to a trip, which proved extremely useful on the very rainy winter day we tested it. It holds up well on rough surfaces despite the bigger wheels and extra heft, plus it doesn’t feel out of hand when cornering fast, rolling into a predictable understeer rather than quickly losing traction.

But if you’re in any way conscious of your budget, consider the Edition One. It doesn’t lack any of the key things that make the S5 great, and you get to pocket enough money to buy a second used car.

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.

Audi’s five-year/unlimited kilometre warranty is starting to fall behind the industry standard, though is about normal for a premium brand. On top of this, customers can opt to purchase extra years of warranty up to a maximum nine years which costs $3590.

Audi does also offer 12 years of bodywork manufacturing warranty against corrosion or perforation. There’s also five years of Audi roadside assistance.

Servicing intervals for the A5 come in at every 15,000km or 12 months, with customers able to purchase fixed-price servicing plans at a discount compared to paying per service.

A five-year servicing pack for the A5 Sedan is $3360, and for the S5 it’s priced at $3540.

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.