Audi RS3 vs Mercedes-Benz CLA45

What's the difference?

If conventionally powered cars really are on the endangered list, it’s vehicles like the Audi RS3 that will remind us what we’ve lost. There’s so much fun to be had in this car, that you really need to take it to a track to tap into it safely and responsibly. And there’s the rub.

While there’s no doubting the RS3’s potential, neither is there any doubt that the driveline absolutely dominates the experience. In fact, we reckon the S3 with its more modest (but still ample) performance and friendlier nature is probably the smarter car for the everyday. It’s also cheaper by about $20,000 and while it lacks the aggressive looks, it’s still a charming car. Perhaps all the more charming for its easier-going nature and balance of abilities.

So why buy the RS3? Because it’s the one that will keep you entertained for longer if you’re a serious enthusiast driver. But if you don’t plan to use the car for track days, there’s a strong argument that the RS3 is way more car than you’ll ever need. Of course, that sentiment never stopped performance-car lovers, did it?

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.

While the overall shape of the RS3 suggests evolution rather than revolution, the RS3 treatment has led to a much sportier look. We still reckon the sedan is the pick of the two body styles, mainly because it looks a bit more aggressive. Certainly, though, an aggressive look is not something either version backs away from, and those deep, wide blacked-out honeycomb grilles front and rear give the thing lots of presence.

So too do the blistered fenders, allowing for the extra track width that gives the RS3 its unique footprint. The front track itself is 30mm wider, but the wider fenders also gave Audi the chance to do some creative aero-management. Unlike, say, the Toyota Supra, for instance, with its faux vents up each side, the RS3’s lower-front vents and aero-slits behind each front fender are fully functional, directing air into the engine bay and away from the brakes respectively.

Another really neat function is the LED daytime running lights’ one-act play when you unlock the doors. As the car unlocks its doors, the LEDs spell out `R’, `S’ and `3’in sequence. Blink and you’ll miss it, but it’s a lovely touch that some manufacturers will never understand.

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.

Like the rest of the Audi A-series range, the RS3 is available in two body styles, a five-door hatchback and a four-door sedan. The five-door hatchback layout is the most practical of the two RS3 layouts, but both feature plenty of front-seat space and a rear seat that folds 40:20:40. 

Paddle shifters are mounted on the steering wheel rather than the column, so they move with the wheel. That can make it difficult to select the correct paddle in a hurry with lots of lock applied.

The Drive modes are operated by a switch low down on the centre-stack that is clearly designed for left-hand-drive cars. It’s too far from the driver and needs to be cycled through in one direction, rather than being able to select the next mode or the previous one.

Beyond that, the interior is a lesson to other car-makers on how to get an interior right. There’s a quality look and feel with the possible exception of the plastic trim below the passenger-side air-vents which looks and feels a bit cheap. There are plenty of cup-holders and cubbies around the cabin with two USB plugs in the front and two in the rear (for charging).

The RS3 loses some space compared to the regular A3 because of the performance hardware. Where the hatch can take 282 litres with all seats in place (1104L with second row stowed), the sedan can swallow 321 litres.

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…

While the five-cylinder engine is more or less a carry-over from the previous RS3 model, the end result is still a pretty stunning one. With 2.5 litres of capacity, the turbocharged unit accounts for 294kW of power (the same as the previous model) and 500Nm of torque (up 20Nm).

The transmission is a seven-speed dual-clutch unit that is quite a familiar sight around Audi by now, and the all-wheel-drive system uses a centre differential with an electronic clutch-pack on each rear axle to give the car a Drift mode (although Audi insists you don’t refer to it in those terms) as well as torque vectoring with the ability to shift 100 per cent of rear-axle torque to the either wheel to maximise grip.

There’s now also an RS-specific exhaust system with an active flap to increase or tame exhaust noise according to which drive model is selected. The drive modes themselves stretch form Comfort to Auto to Dynamic, altering shift points, gear-shift aggression, throttle response and suspension firmness as well as that exhaust flap.

Brakes are enormous 375mm front rotors with six-piston calipers, that hardware forcing the fitment of a 19-inch alloy wheel (specific to the RS3) for brake clearance.

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.

Audi’s official combined fuel consumption figure for this car is 8.3 litres per 100km. Obviously, start using all that power and torque and that figure will grow significantly. Based on that, the car emits 190 grams of CO2 per kilometre, and with the 55-litre tank (which looks a bit small on paper) the range should still be around 600km between fill-ups.

The only catch with that is the high-tech nature of the engine means it requires the more expensive, Premium ULP at the bowser.

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.

First impressions are that this is a typical Audi in the way it fits together beautifully and is made from quality materials. The ergonomics – particularly the virtual cockpit - are spot on and it even smells like an Audi. Noise is well suppressed, the controls feel quality and the front seats are comfy. But from there, the overarching view is dominated by that powerhouse of an engine.

This isn’t just a quick car, it’s actually brutal in the way it builds boost almost immediately and then hurls the car down the road. To be honest, it’s almost too much, and the way the RS3 reels in the horizon will leave some drivers ignoring other sensory inputs in order to keep up with the car. Brutality breeds brutality, too, and the subsequent steering and braking inputs required when the throttle is pinned will not always be the considered, gentle type; they’ll often be gut reactions.

Thankfully, the rest of the driveline and platform has the smarts to make all this work. There’s awesome grip from the Quattro all-wheel-drive system and the car stays flat and steers in a fast, neutral but pin-sharp way. The dual-clutch transmission feels perfect for the engine, too, with ultra-quick shifts that become more aggressive as you ramp up the drive modes. Ride quality is good but we reckon there’s less bandwidth in the various drive mode settings than exists in the same system fitted to the S3 model we drove a few months ago. While the latter offered a broad range of suspension firmness, the RS3 seems to be a bit of a prisoner of its own performance, with Audi leaning all the drive modes towards a firmer setting in the name of body control.

That’s supported by Audi’s decision to offer us some race-tack laps in the RS3 to safely explore its high-end tendencies. At this point, the car emerges as a proper track-day proposition, all that power and control blending into a car that loves being thrown around a circuit. Perhaps the front seats could do with a little more side bolstering at track-cornering speeds, but overall, it’s clear that the RS3’s brief does, indeed, include a degree of race-track use.

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.

Service intervals for the RS3 are every 12 months or 15,000km, whichever comes first. Audi offers capped-price servicing for the RS3 at $3580 which covers servicing costs for the first five years.

The car is covered by Audi’s five-year/unlimited kilometre warranty. The vehicle is also protected against body-rust perforation for 12 years.

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.