Audi RS5 vs Mercedes-Benz CLA45

What's the difference?

Good looking, good to drive, and good to simply sit in, the Audi RS5 range ticks plenty of premium boxes. Whether you can live with the practicality pitfalls of the Coupe is up to you, but if you can't, might I suggest taking a wander over to our RS4 Avant review?

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.

I defy anyone to describe the RS5, and especially the Coupe, as anything but stunning. Seriously, the near perfect proportions and swept-back styling make it look fast even when it's parked. 

Up front, there's a new-look black-mesh grille that's been given a 3D effect, like it juts out over the road in front it, while the thing headlights have been carved back into the body work like they're been windswept under hard acceleration.

The 20-inch darkened alloys fill the arches, too, with a sharp body crease that runs from the front headlight all the way back to the bulging shoulder lines above the rear tyres accentuating the curves.

Inside, the RS5 is a sea of black Nappa leather and sporty touches, and we particularly like the chunky, flat-bottomed steering wheel, which both looks - and feels - great.

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.

We only tested the Coupe, and I can tell you that the practicality perks on offer largely depend on where you're sitting.

Up front, you're spoiled for room in the two-door Coupe, with the two spacious seats separated by a sizeable centre console that's also home to two cupholders and a variety of cubbies, with extra bottle storage in each of the front doors. 

The back seat, though, is a little, or a lot, tighter, with come acrobatics required to even climb into it, given the Coupe only has two doors. The Sportback offers two more doors, which will surely make the process a little easier. 

The Coupe measures 4723mm in length, 1866mm in width and 1372mm in height, and will deliver a decent 410 litres in luggage space in the boot. The Sportback measures in at 4783mm, 1866mm and 1399mm, and boosts your luggage space to 465 litres.

Either vehicle has your tech needs sorted, with an abundance of USB and power outlets serving both front and backseat riders.

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.

Priced from $111,200 plus on-road costs, the CLA 45 S is a staggering $20,530 dearer than its non-S predecessor. Yep, it’s a hard number to digest at first, but Mercedes-AMG says the premium is justified due to a significant step-up in specification.

Standard equipment not already mentioned includes dusk-sensing lights, rain-sensing wipers, a tyre repair kit, power-folding side mirrors with heating, rear privacy glass, satellite navigation, Apple CarPlay and Android Auto support, digital radio, a 590W Burmester sound system with 12 speakers, keyless entry and start, dual-zone climate control, power-adjustable front seats with heating, an auto-dimming rearview mirror and LED ambient lighting.

Key options include the $2490 'AMG Aerodynamics Package' (high-gloss black front splitter, aero flics and larger bootlid lip spoiler), $3290 'AMG High Performance Seat Package', $790 cooled front seats and $790 'Communications Package' (windshield-projected head-up display). Only the latter was fitted to our test vehicle alongside no-cost 'Polar White' paint.

The CLA 45 S only has one direct rival, the $86,500 Audi RS3 sedan, although the $106,900 BMW M2 Competition coupe is more or less in the same league. Either way, the CLA 45 S is in another league when it comes to price and performance.

But you could also opt for its A 45 S hatch sibling for ‘just’ $93,600…

Its a terrific engine, this - a twin-turbo 2.9-litre six-cylinder TFSI that will deliver 331kW at 5700rpm and 600Nm at 1900rpm, sending it thundering to all four wheels (because quattro) via an eight-speed tiptronic automatic.

That's enough, says Audi, to deliver a 0-100km/h sprint time of 3.9 seconds in the Coupe and the Sportback. Which is very, very quick.

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 RS5 Coupe will sip a claimed 9.4L/100km on the combined cycle, and emit a claimed 208g/km of Co2. It's fitted with a 58-litre fuel tank. 

The RS5 Coupe will the same 9.4L/100km, but emit 209g/km of Co2.

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.

With our time behind the wheel limited to the RS5 Coupe, we can only really report on how the two-door feels on the road, but given the prodigious power on offer, it's unlikely the addition of two doors is going to make the Sportback any slower. 

In short, the RS5 is thunderously fast, collecting speed with utter nonchalance thanks to this thick and endless-feeling supply of power unleashed whenever you plant your right foot.

It makes even the most ham-fisted attempts at cornering feel fast as lightning, with the power flow able to make up for every slow entry and exit by simply piling on pace between bends. 

But that's what you expect from an RS model, right? So perhaps more impressive is the RS5's ability to transform back into a relatively sedate urban cruiser when the red mist subsides. The suspension is firm, especially over rough road surfaces, and you do need to be a little careful with the accelerator to avoid that lurching feeling at every green light, but driven calmly, it doubles as a everyday car quite nicely.

Like in the RS4, we did find the gearbox felt a little quick to change at pace, shifting up or down at strange moments on the way into or out of corners, but you can reclaim control via the paddle shifters.

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.

ANCAP awarded the CLA range (excluding CLA35 and CLA45 S) a maximum five-star rating in 2019.

Advanced driver-assist systems (impressively) extend to autonomous emergency braking, lane-keep assist, active blind-spot monitoring, cross-traffic alert, adaptive cruise control, traffic sign recognition, high-beam assist, driver-attention alert, hill-start assist, tyre pressure monitoring, park assist, surround-view cameras and front and rear parking sensors. Yep, you’re not left wanting here.

Other standard safety equipment includes nine airbags (dual front, front and rear side, and curtain plus driver’s knee), the usual electronic traction and stability control systems, anti-skid brakes (ABS) and brake assist (BA), among others.

Audi vehicles are covered by a three-year, unlimited-kilometre warranty, which is feeling more than a little underdone when compared to some competitors.

Services are due every 12 months or 15,000kms, and Audi allows you to pre-pay your service costs for the first five years, at a cost of $3,050.

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.