Mercedes-Benz CLA45 vs Audi S3

What's the difference?

The new CLA 45 S has knockout performance to match its knockout looks, neither of which are much of a surprise given the ingredients involved.

That said, it is far from perfect, with questions raised over its value and practicality. And for those reasons, we’d be buying the A 45 S hatch instead.

Is the new CLA 45 S worth such a hefty premium over its non-S predecessor? Tell us what you think in the comments below.

The updated Audi S3 Sportback is a fun-sized dynamo with impressive outputs and athletic road manners. It’s missing a few premium features, but its compact size paired with a gutsy engine makes it a compelling option for drivers who don’t want to compromise on performance (just space).

There’s simply no mistaking the CLA 45 S from its CLA siblings. It’s angry and stylish, at the same time.

Up front, Mercedes-AMG’s signature 'Panamericana' grille insert is large and in charge, flanked by adaptive 'Multibeam' LED headlights that incorporate sinister-looking daytime running lights (DRLs).

The real action, however, is happening below, where the AMG body kit starts to come into frame. It’s delightfully chunky and highlighted by cavernous side air intakes, which hint at the sledgehammer residing beneath a bonnet featuring prominent power domes.

Around the side, the CLA 45 S does its best impersonation of a coupe, with a sloping roof line and a curvaceous glasshouse. It also brings the aggro with a particularly sporty set of 19-inch alloy wheels, which flank pointy side skirts.

At the rear, the CLA 45 S again hints at its performance level, this time with a bootlid lip spoiler, although look past its LED tail-lights and you’ll find the star of the show, a furious diffuser that houses the quad 90mm tailpipes of the AMG sports exhaust system.

Inside, the CLA 45 S is pretty special. While the CLA certainly provides the building blocks, it goes a step further with a number of unique touches.

Your eyes are immediately drawn to the wickedly cool 'Dinamica'-trimmed AMG Performance steering wheel, which not only has paddle-shifters, but also features two ‘display buttons’ that make adjusting vehicle settings on the fly super easy.

Then there are the front sports seats, which are covered in Lugano leather upholstery alongside the armrest door inserts, while artificial cow hide trims the upper dashboard and door shoulders.

Hard plastics? You’ll need to look lower than the soft-touch middle dashboard to find them, as they are primarily confined to the lower sections of the cabin. And yes, some of the switchgear is very cheap for a six-figure performance car.

One personal bugbear, though, is the liberal use of gloss-black trim for the centre stack and console. Not only is it a fingerprint magnet, but it scratches easily, too. The brushed stainless-steel and silver accents elsewhere are nice, though.

While stainless-steel sports pedals also help to make the CLA 45 S stand out from the CLA crowd, it is otherwise a carbon-copy of its siblings, which is no bad thing.

Of course, the headline act is the pair of 10.25-inch displays, with one a touchscreen that is partially concealed by the steering wheel, while the other is a digital instrument cluster.

The former delivers the now-familiar 'MBUX' multimedia system, which is still at the cutting edge when it comes to functionality, especially with its always-on natural voice recognition, which is as good as it gets, albeit not perfect.

There are, of course, more input methods, with two small touchpads located on the steering wheel, while a larger item sits on top of the centre console, supported by a palm rest. There are also shortcut buttons and physical climate controls.

The S3 Sportback may be a small car, but its S design features, like the stylised blackout grille, matrix LED headlights, and 19-inch alloys with red brake calipers, give it a distinctly athletic and fun-loving vibe. It’s compact, but definitely not diminutive and carries serious road presence. It’s hot hatch meets fun-size.

Inside, the S3 looks fabulous. Integrated ambient lighting, a sharp dashboard treatment and a driver-focused cockpit all lend it a premium feel.

The front seats look properly sporty with their integrated headrests, and the quilted Nappa leather upholstery feels great, especially with the eye-catching red contrast stitching.

As for technology, it’s as high-end as you’d expect with a 10.1-inch touchscreen multimedia display and 12.3-inch digital instrument cluster taking centre stage.

The only drawback? No sunroof. Combined with the black headliner and compact cabin, it can feel a little gloomy at times. Still, it’s a cabin you’ll enjoy spending time in.

Measuring 4693mm long, 1857mm wide and 1413mm tall, the CLA45 S is actually similar in size to a C-Class but not quite as practical.

Cargo capacity is pretty good, at 460L, but can be increased via the 40/20/40 split-fold three-seat rear bench stowed – an action that can be performed via the boot’s manual release latches, although it doesn’t tumble forward by its lonesome.

Speaking of the boot, four tie-down points are on hand for to help loose loads alongside two side storage nets. Bulkier items will have to contend with a tall load lip. That said, the boot’s aperture is much wider than before, which is good news.

In-cabin storage options are okay, with the glove box decently sized and the map pockets of the net variety, while the central bin is fairly average, although it does house two USB-C ports.

There’s also a standard sunglasses holder and a cubby in front of the centre console’s two cupholders. It isn’t that useful, though, as the wireless smartphone charger takes up most of space alongside a USB-C port and a 12V power outlet.

The front door bins can accommodate two regular bottles each, while their counterparts in the rear take only one apiece. That said, the second row does have a fold-down armrest with another pair of (flimsy) cupholders.

Rear occupants don’t have a whole lot of room to play with, though. Legroom behind my 184cm driving position is pretty decent, at around four centmetres, but headroom is not. In fact, it’s non-existent sitting upright, with the panoramic sunroof not helping matters.

Toe-room is also at a premium alongside precious footwell space, which is reduced by the tall transmission tunnel. As such, the second row is best for up to two adults or three children at a time.

And if there are three occupants abreast, they’ll have to compete for the two USB-C ports, which are located in a fold-out cubby below the central air vents at the rear of the centre console.

For reference, child seats can be fitted in the second row thanks to top-tether and ISOFIX anchorage points, although both are only available for the outboard seats.

Like most hatches, the front row enjoys the most space. While it’s cosy, it never feels cramped. The seats are firm yet comfortable, thanks to their adjustability and expandable under-thigh supports. Access is fairly easy with wide door apertures, though the low seating position might earn a few grunts, especially from taller folks.

Storage up front is well sorted, with a glove box, a small centre console, a dedicated phone cradle and a couple of cup and bottle holders. It’s about what you'd expect for a car this size, but it's enough to keep things tidy.

There are plenty of charging options, with two USB-C ports in each row and a wireless charging pad up front.

The multimedia system is intuitive and easy to use. The touchscreen is responsive, and wireless Apple CarPlay connected without fuss and stayed connected all week. Wireless Android Auto is available, too.

Built-in sat nav is clear, and I love the way directions pull through to the digital instrument panel. The Sonos sound system? Pretty darn good. My son and I had more than one mini-concert on the school run.

As for the rear row, it definitely reminds you this is a small car. At 168cm, I found it on the cramped side of cosy and my husband just laughed when I asked him to try it! The wheel arch also cuts into the door aperture, making access a little awkward. Best to think of it as occasional adult seating. But given the size, that’s no surprise.

Amenities in the back are decent with a couple of map pockets, cup and bottle holders, as well as a fold-down armrest, those USB ports and rear temperature control (but curiously, no fan control). The seats are comfortable enough, but space is limited. Realistically, it’s best suited for two passengers, not three.

Boot space is quite practical. The wide opening and manageable load lip height make it easy to slide items in and out. It offers 325L of space, less than its key rivals, but expands to 1145L with the rear seats folded flat. The handy 40/20/40 split also adds versatility. Under the boot floor, you’ll find a tyre repair kit.

The A3 Sportback comes in three trim levels, with the S3 technically sitting in the middle, just below the performance-focused RS 3. It's priced from $78,800, before on-road costs, and it shares the same platform and underpinnings as the Volkswagen Golf R. Surprisingly, our test vehicle isn’t significantly more expensive than its Golf R rival which comes in at $70,990 MSRP.

That makes it a more affordable option when compared to premium rivals like the BMW M135 xDrive which starts at $83,600 MSRP and the Mercedes-AMG A35 which comes in at $89,700 MSRP.

The update sees engine outputs improve with it gaining 17kW and 20Nm of torque, resulting in a total of 245kW and 420Nm.

Feature highlights include 19-inch alloy wheels, red brake calipers, electrically-adjustable and heated front seats (with expandable under-thigh support), rear privacy glass, quilted Nappa leather upholstery and 'S Sport' suspension with damper control which lowers the ride height lowered by 15mm.

The updated technology is well-rounded and now comes with wireless Apple CarPlay and Android Auto. There's also three-zone climate control, a 10.1-inch touchscreen multimedia display, a 12.3-inch digital instrument cluster, digital radio, four USB-C ports, a wireless charging pad, built-in satellite navigation and a 15-speaker Sonos 3D sound system.

Still, despite its premium hot hatch status, this grade skips a few luxury touches. Ventilated front seats, a heated steering wheel, heated rear outboard seats and a sunroof are all missing. The BMW M135 xDrive, notably, includes all of these as standard.

Even the powered tailgate with kick-functionality is an optional extra here, adding $660 to the price. At this level that should be standard.

The CLA45 S is motivated by the most potent series-production four-cylinder engine yet.

The 2.0-litre turbo-petrol unit punches out an astounding 310kW of power at 6750rpm and a significant 500Nm of torque from 5000-5250rpm – a marked 30kW/25Nm improvement over its non-S predecessor.

It’s also worth noting Mercedes-AMG performed “torque shaping” to make the new engine’s output delivery (or curve) akin to that of a naturally aspirated unit. This attitude also led to a screaming redline of 7200rpm.

An eight-speed dual-clutch automatic transmission is responsible for swapping gears, while Mercedes-AMG’s fully variable '4Matic+' system sends drive to all four wheels, although it does have a 'Drift Mode' that effectively disengages the front axle.

With the help of standard launch control the CLA 45 S sprints from a standstill to 100km/h in four seconds flat, while its top speed is electronically limited to 270km/h.

The S3 Sportback wears the quattro badge proudly, meaning it’s all-wheel drive and it pairs a tweaked seven-speed automatic transmission with a 2.0-litre turbocharged, four-cylinder petrol engine.

This update brings a bump in performance over the previous model, including the addition of a rear torque splitter. Power is now up to a gutsy 245kW and 420Nm of torque, launching the S3 from 0 - 100km/h in just 4.7 seconds. That’s proper hot hatch territory.

Fuel consumption on the combined-cycle test (ADR 81/02) is 8.9 litres per 100 kilometres for the CLA 45 S, while its claimed carbon dioxide emissions are 202 grams per kilometre. Both are pretty keen given the level of performance on offer.

In our real-world testing, we averaged 12.0L/100km over 270km of driving evenly split between city traffic and highways. This result was somewhat inflated by some ‘spirited’ driving but is certainly something we can learn to accept.

For reference, the 51L fuel tank in the CLA 45 S takes 98 RON premium unleaded petrol at minimum.

The S3 Sportback has an official combined fuel consumption figure of 7.9L/100km and a 55-litre fuel tank, giving it a theoretical driving range of up to 696km.

Its key rivals hover around similar numbers, so it's right on the mark for the segment. After a mix of long-distance drives and my usual urban errands, my real-world figure came in at 8.0L/100km - very close to the claim, which I’m pretty happy with.

When it comes to sheer driving pleasure, the CLA 45 S is a huge step-up over its non-S predecessor.

Of course, the 2.0-litre turbo-petrol four-cylinder engine will steal all the headlines, and rightfully so; it’s the most potent unit in its class by some margin.

In reality, it absolutely slaps. Simply put, acceleration is addictive, and not just because of the outputs, but also the way in which they’re delivered.

The CLA 45 S does its best impression of natural aspiration, and I can’t help but award it an automotive Oscar.

Don’t get me wrong, performance is still strong down low (despite a hint of turbo lag), with it progressively building into, and through, a hard-hitting mid-range before reaching a knockout top end that you’ll want to revisit time and time again.

That said, it does take two to tango, and what a dancing partner the eight-speed dual-clutch automatic transmission is.

It’s almost flawless, with its gear changes stereotypically super quick but uncharacteristically buttery smooth at the same time.

Responsiveness is another strong point, although it does sometimes have difficulty recognising when the fun is over, as it can hold onto the short lower gears for a little longer than necessary.

And despite our initial fears, the CLA 45 S is still very, very vocal, with its sports exhaust system serving up plenty of aural pleasure, albeit not quite as much as the original CLA 45.

The soundtrack is booming and is complemented by plenty of pops on downshifts and the overrun as well as frightening crackles when aggressively up-shifting . But these theatrics require the Sport Plus drive mode to be engaged, which opens up an all-important exhaust valve.

Given the level of performance on offer, you’d be right to assume the CLA 45 S has a firm ride, but it’s actually better balanced than most.

The 'AMG Ride Control' sports suspension on hand consists of MacPherson-strut front and multi-link rear axles with three-stage adaptive dampers, which progressively stiffen things up.

However, all is relatively comfortable, even in the stiffest setting. In fact, only sharper edges are felt. It’s more than liveable, especially considering the benefits of the trade-off.

Speaking of which, the CLA 45 S loves to eat up corners. Handling is more or less neutral when pushing hard, at which point its 1687kg kerb weight starts to be felt.

Nonetheless, body control is very strong, partially thanks to the reinforced chassis, with only a hint of roll encountered when cornering with intent.

A lot of the credit has to go the fully variable 4Matic+ all-wheel drive system with rear torque vectoring, which provides outstanding grip, even in the poorest of conditions.

In fact, it bestows such confidence you'll want to push harder to try and find the limits of adhesion. A staggering effort.

The CLA 45 S isn’t without its flaws, though, with the electric power steering on tap good but not great.

It’s speed-sensitive and has a variable ratio, which mean it’s pleasingly light in hand at low speed and noticeably heavier at high velocity, with the latter exacerbated when playing with the available drive modes.

Either way, it’s nice and direct and provides a good amount of feedback through the wheel, but we feel Mercedes-AMG could’ve taken it even further in these two departments to really mix it up with genuine sports cars.

What isn’t half-baked, though, is the 'AMG High Performance braking system', which consists of 360 x 36mm front and 330 x 22mm ventilated discs with six-piston fixed and single-piston floating red callipers respectively.

This set-up washes away speed with ease, instilling the driver with even more confidence when tackling a winding road, while pedal feel is good. Yep, the CLA 45 S decelerates nearly as well as it accelerates.

The S3 Sportback sounds as mean as it looks, and it delivers on that promise with effortless grunt. Acceleration is immediate, with plenty of power on tap when you need it. It’s just fun all around.

The lowered sports suspension and wide tyres do bring some extra noise into the cabin, even at lower speeds. You might find yourself repeating things to rear passengers now and then, but it never feels overwhelming.

Steering and suspension are on the firmer side, so yes, you’ll feel the bumps but the payoff is sharp, responsive handling. Quick lane changes and winding coastal roads are where this car shines.

Visibility is about what you’d expect from a low-slung hot hatch. The pillars don’t obstruct the view, but sitting beside a towering SUV at the lights can make you feel a bit... compact.

Cornering is a strong suit, thanks to the car’s wide stance and AWD system. It feels confidently planted in most conditions. That said, I noticed the occasional wobble through the rear frame on rough sections in heavy rain.

Its compact size makes parking a breeze, especially with the help of multiple sensors. The reversing camera is crisp, but at this price point, the lack of a 360-degree camera view feels like a missed opportunity.

The S3 isn’t covered by its 2WD sibling's maximum five-star ANCAP safety rating but it is well-equipped with safety features all the same.

Safety equipment includes blind-spot monitoring, side exit assist, rear cross-traffic alert, lane departure alert, lane keeping aid, park assist, reversing camera, front/rear parking sensors, forward collision warning, autonomous emergency braking and adaptive cruise control with stop and go function. 

It also has six airbags but misses out on a front centre airbag. None of the driver assist systems are intrusive to daily driving, which I always like.

The rear row has ISOFIX child seat mounts and three top-tether anchor points but only two child seats will fit.

Like all Mercedes models, the CLA 45 S comes with a five-year/unlimited-kilometre warranty, which sets the standard in the premium market. Better yet, five years of roadside assistance is also bundled in.

CLA 45 S service intervals are every 12 months or 20,000km, whichever comes first. A three-year/60,000km capped-price servicing plan is available for $3750, which is not cheap. That said, its pricing can be reduced by $750 if paid upfront alongside the vehicle.

Audi backs the S3 Sportback with a five-year/unlimited kilometre warranty, which is on par with its European rivals. A five-year pre-paid servicing plan is available for $2890 which is cheaper than pay-as-you-go and reasonable for the class.

For those looking to go the extra mile, the 'Audi Advantage' package lets you extend the warranty and capped-price servicing by an additional two years, which represents solid value overall.

Servicing intervals are every 12 months or 15,000km, whichever comes first.