Mercedes-Benz CLA45 vs BMW 3 Series

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.

I thoroughly enjoyed my time in the BMW 320i M Sport. It’s fun to drive and I felt connected to what the car was doing on the road. The harder ride may not appeal to some but I didn’t mind it. The cosy back seat and boot mean it will probably suit a smaller family best and one which doesn’t have to worry about carrying a lot of gear around regularly, but it suited my needs just fine.

I reckon this is a car for those drivers who don’t want to compromise on performance but still have a kid or two. If you’re after the cushioned comfort of a Merc, this won’t appeal but I didn't want to give this one back and happily give it a firm 8/10.

My son liked the sports car looks and enjoyed the amenities in his row. He gives it a 10/10.

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.

Sharper than its predecessor, the new 320i has LED everything with the rear lights being longer and curving around to the sides of the car.

The classic 'kidney' grille is darkened and more pronounced, with the black panelling extending to the rear to create an unapologetically sporty presence. A presence that’s accentuated by the twin exhausts.

The batcave interior with its black headliner, black seats… black everything, looks smart and stylish.

You do have a fair bit of harder touchpoints throughout but the customisable ambient lighting helps to soften the overall effect.

With its 2068mm width, 4709mm length and 1435mm height, the sedan makes its presence known without feeling cumbersome to manoeuvre. Urban dwellers need not fear their local car park!

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.

For such a sleek looking sedan, it’s generous up front with plenty of head and legroom.

You can adjust the seat to sit quite low and both front seats have extendable under-thigh supports, which should excite taller drivers. 

My 189cm (6’2”) brother has the 328i and is very comfortable but taller front passengers will encroach on back seat passenger comfort.

The front seats are quite firm on the backside, they also lack adjustable lumbar support, so expect to stretch the kinks out on a longer trip.

The amenities and tech feel well thought out and easy enough to use. The 12.3-inch touchscreen multimedia system looks great and has the best-looking graphics I’ve sampled.

The BMW system is intuitive to use once you get used to it. If you’re not interested in using the touchscreen, you can also utilise the rotary-wheel for menu selections.

There’s also Bluetooth connectivity, wireless Apple CarPlay and Android Auto plus built-in satellite navigation.

The 12.3-inch digital instrument panel is customisable and the information displayed simply but you won’t really look at it because of the head-up display.

Front occupants enjoy a wireless charging pad for their smart phone, a USB-A and USB-C port plus a 12-volt socket. Rear passengers get a couple of USB-C ports, too.

The storage is good for this size sedan but overall passenger room takes priority, but the glove box and middle console will suffice for everyday use.

While it may not excite others, I love the big bottle holders in the doors. They’re large enough for my big 1.5L bottle and angled for easy access. These are found in the rear doors as well.

Back seat passengers enjoy climate control, directional air vents, two cupholders, netted map pockets and reading lights.

My six-year old was happy with the amenities and lower ground clearance because he felt comfortable and had his independence.

The boot offers a good capacity of 480L and the aperture isn’t too narrow, so you can comfortably access items if they roll to the back.

I had plenty of room for my little family’s needs but if you’re a larger family, you may need to get strategic with gear storage.

Being a base model, you do miss out on a powered tailgate, which is a shame but not too much of an issue given this is a sedan and the lid isn’t heavy.

There’s also no spare tyre or even a puncture repair kit but you have run-flats, so you should be able to limp to a service centre if need be.

There are seven variants for the BMW 3 Series sedan and our model is the base model for the petrol variants.

There is a plug-in hybrid version, the 330e, if you’re after a more fuel-efficient option but it will up the price by about $20K.

As it stands the 320i M Sport is $78,900, before on-road costs. Our model has been finished in 'M Brooklyn Grey', which adds $1539 to the price.

That puts it at a similar price point as its rivals. You get a well-specified package with the M Sport but it doesn’t have the same sense of cushioned comfort as the Merc does, but more on that later.

Still, the sporty and streamlined interior is headlined by BMW’s dual 12.3-inch screens that sit propped on the dash like a futuristic cockpit.

The mix of synthetic leather and cloth seats are electric and have adjustable side bolsters for when you want to go hard in a turn.

The interior also boasts a sunroof and wireless Apple CarPlay and wired Android Auto. There are some other highlights like the 18-inch alloy wheels, leather steering wheel and the crystal-clear head-up display, to name a few. 

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 320i M Sport has the ‘baby’ engine in the 3 Series line-up but the 2.0-litre, four-cylinder turbo-petrol powertrain still delivers on power with a maximum output of 135kW/300Nm. 

This is a rear-wheel drive and has an eight-speed auto-transmission which delivers very smooth gear changes.

Despite having the smaller engine, it can still go from 0-100km/h in just 7.4 seconds.

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.

In a world with rising fuel prices, the efficiency of this decently powered sedan should excite you.

The official combined fuel cycle is 6.5L/100km. Real world testing saw my figure at 7.4L/100km after a mix of open-road and urban driving this week.

I thought that was great for how hard I drove it and for the power, you won’t be wincing when you put your foot down. I would expect it to be higher in an urban setting.

The 320i has a 59L fuel tank and based on the official combined cycle figure, you should get just over 900km of driving range, which is great, especially if you do 'roadies' like me!

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.

There's a lot that I like about how this performs but a highlight is how eagerly the car responds when you accelerate.

However, it’s not unbridled power. There’s no bucking at the front or shuddering through the steering wheel. It’s controlled but still very fun.

The lower centre of gravity and coupe-like height of this does mean it handles corners well and the bolstered seats hold you firmly into place, meaning you can be free to drive this a little harder than you might normally. Which I did and can confirm it handles itself well.

This has the M Sport suspension, which means it’s stiff, but you feel very connected to the road.

You do get a lot of talk-back from bumps in the road but unless you hit a big pothole, you never feel rattled by them.

But it is a harder ride than other luxury models, which doesn’t bother me as I like the handling, but if you want limo-like comfort, look elsewhere.

The cabin is very nice to spend a lot of time in and relatively quiet, even at higher speeds.

The 11.4m turning circle and sleek dimensions makes it very handy to park, even in tight car parks. The nose is long but the front and rear parking sensors take out any ‘will I make it’ moments and the super clear reversing camera is great. 

The safety list includes a suite of features and the following come as standard: adaptive cruise control, auto emergency braking (operational from 5.0-210km/h), blind-spot monitoring, speed sign recognition, forward collision warning, SOS emergency call button, daytime running lights and rear cross-traffic alert.

I like the intelligent seatbelt reminder and that the bonnet is considered 'active', meaning it will lift up and away from the engine if the sensors detect that a pedestrian has been hit.

However, I have to call out the lane departure and keeping aids. It’s a hit or miss system and I tested it extensively this week once I noticed it.

You can customise the sensitivity levels and even on the highest sensitivity, it works too sporadically for my liking. BMW should improve this system for future instalments.

The 3 Series has been awarded a maximum five-star ANCAP safety rating but it was done a while ago in 2019. It only has seven airbags and is missing the newer front centre airbag. 

There are ISOFIX child seat mounts on the outboard seats and three top tether anchor points but the back seat is a bit too narrow to comfortably fit three child seats side by side.

You'll be able to fit a 0-4 rearward facing child seat but may struggle if you're a tall family.

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.

The 320i comes with a five-year/unlimited km warranty, which is standard for this class.

You can choose between a three- or five-year capped-priced servicing plan. The five-year plan costs just $2150, or $430 a year, which is competitive for this class.

Like other BMWs, servicing intervals are condition-based, with the car letting you know when it needs to be serviced.