BMW M4 vs Mazda CX-30

What's the difference?

We cannot think of a faster or more invigorating four-seater luxury convertible for the money than the new M4 Competition.

Finally, after years of devastatingly fast droptops with remote steering and an unforgiving ride, the G83 generation discovers refinement and sophistication to go with its supersonic speed.

There’s terrific talent on tap here that no rival can even come close to right now. BMW is on a roll and this is the first M4 convertible that can sit proudly alongside the best of its classic M3 ancestors.

About to enter its fifth year in market the Mazda CX-30 is holding up well and this GT SP FWD grade delivers solid value relative to its key competitors, of which there are many. It’s also space-efficient, practical and performs well with top-shelf safety, decent refinement and good dynamic ability.

Alternately, it’s crying out for a hybrid powertrain to improve fuel efficiency, the interior form and function is starting to date and while it meets the market the ownership promise could be sharper. But this little SUV is still worthy of a spot on your new-car short list.

Hallelujah! The unloved folding hardtop is history and fabric is back in fashion in a BMW 3/4 Series-based convertible for the first time since the demise of the E46 convertible in 2006.

It improves the proportions and aesthetics out of sight while remaining superbly insulated. It’s also 40 per cent lighter to boot while liberating 80 litres of extra luggage space.

The roof requires just 18 seconds to drop away or erect again, and can be done so at speeds of up to 50km/h. And it looks great, with a taut fit that suits the BMW’s lithe lines to a tee. With all four windows dropped, it also does a fab impression of an American-style pillarless hardtop.

Roof up or down, the M4’s muscular styling has a tense sparseness to it that means business, reinforced by that oversized, M-specific kidney grille treatment that, admittedly, isn’t as divisive in real life. The smiley LED light wave out back also brings a friendlier tone, harmonising handsomely with the rest of the car.

This is probably the best-looking BMW convertible since the beautiful E46 era.

Mazda continues to follow a disciplined design path with everything from the MX-5 sports car to the BT-50 dual-cab ute sharing key attributes like the brand’s signature trapezoidal grille, simple flowing lines and sleek head- and tail-lights, all wrapped up with a subtle hint of chrome here and there.

Car-spotters with the GT SP on their checklist should look out for 18-inch black metallic rims as well as black exterior trim, including the mirror caps. 

Inside, the CX-30 maintains Mazda’s restrained approach with smooth surfaces integrated across the multi-layer dash and primo leather-trimmed seats.

That said, this car is starting to show its age with the multimedia screen plonked on the top of the dash (in typical Mazda fashion) and a largely conventional instrument cluster.

Yes, the main dial is configurable courtesy of a central 7.0-inch TFT screen, but next to more recent arrivals boasting sleek, often twinned, flat screen displays the CX-30 looks and feels out of touch. 

Functionally, there’s a sensible mix of digital controls and physical buttons (points for audio volume and ventilation dials!), but… the multimedia screen can only be accessed by a rotary controller in the centre console once the car is mobile (it works as a touchscreen when you’re stationary).

Some say touchscreens take your eyes off the road so the controller makes sense, but with a sequential app like Spotify it can take a lot of twirls to get to where you want to go, which upsets concentration and takes your eyes off the road, anyway. I’d prefer the relative ease of a quick press on a screen.

Aside from all that, the materials used are high quality with soft-touch surfaces across key contact points and hard plastics confined to high-wear areas. 

The M4 Convertible is not a paragon of space efficiency, given its footprint.

At nearly 4.8 metres long and 1.9m wide, the M4 Convertible casts a sizeable shadow on the road, which only really pays dividends for front-seat occupants inside.

Ours was fitted with a very handsome pair of $7500, two-tone M Carbon bucket seats up front, a sort of futuristic tombstone design with a fixed headrest that looks like they were created by and for Stormtroopers; they do provide all the electronic adjustability one would need in terms of fore/aft, up/down and lumbar support movement.

But, unless you really need their g-force-bracing support and love their outrageous appearance, they are monumentally obstructive to effortless entry/egress and overall hip comfort if you don’t possess a gymnast’s physique. In fact, at times, they can feel downright torturous, especially in the gusset area due to the pointless (ironically) hard central bulge bit. The standard front seat set-up is perfectly fine, offering all the comfort and support expected in a luxury convertible, with the added bonus of headrest adjustability.

As with all G20/G80 generation 3/4 Series, the M4’s interior is a welcome return to form for BMW, from the excellent driving position and superb build quality, to thoughtful switchgear placement, brilliant ventilation and ample storage. And iDrive is probably the best and most intuitive multimedia system out there, too, needing no special skill or distraction once mastered.

A quick note about the instrumentation. The 4 Series design digital readouts are prettier than the standard 3 Series' ugly standard screen that looks ex-Honda Civic. This one offers alternative views and is easy to read at a glance. But it still makes us pine for good old analogue dials. Remember when BMWs were the world leaders in dial design?

Some familiarisation is also required to figure out the M part of the M4, including the various driving and performance modes; they’re divided into Road, Sport and Track settings. Yet, thankfully, they’re all far simpler to get your head round than before, which required too much fiddly concentration, since – once quickly learnt – everything is possible with eyes-on-the-road promptness. A new M Mode button offers pre-determined shortcuts to whichever drive combinations are desired.

The roof is well insulated, meaning that previous-gen folding hardtop-owning prospective buyers shouldn’t be too sad about the fabric above their heads. On the go, front occupants can enjoy a variety of configurations, starting with snug coupe-style cosiness and security, moving to cool pillarless hardtop-style windows-only down cruising, to the full top-down convertible glory. The latter also brings minimal buffeting at speed unless you’re stuck out in the back. Roof-up vision isn't brilliant, though.

Strangely, with the M Carbon bucket seat options ticked, it’s actually easier for some people to get into the back than the front. Pulling a strap sees the front bucket seats (slowly) whir as far forward as possible to allow sufficient room for people to clamber onto the rear seats.

Once sat, it’s clear that longer-legged people will struggle. Knee room is OK (especially if the front occupants are feeling sympathetic by moving their seats forward), there’s surprisingly adequate head room for your 178cm tester when slightly slouched, big feet can be tucked beneath the front seats and scalps never have to touch the rear glass thankfully.

And at least BMW has tried to make life back there comfier for smaller people, due to rear-facing air vents with climate and directional control, two USB-C ports, a pair of cupholders, a centre armrest and some handy storage. The materials are of a high quality construction, too.

However, the fixed back rest is far too upright, the knees-up posture quickly gets tiresome, the cushion is firm and you’re sat on a slight angle pointing outwards. Claustrophobics won't be too happy either. Annoyingly there aren’t side window buttons either, meaning only the driver can lower or raise them. The two-seater back seat is best saved for short trips or kids.

Happily, once the roof is dropped, the hemmed-in feel vanishes, there’s not too much wind intrusion or buffeting with the side windows up and there’s a sense of shared freedom that only a four-seater convertible can bring. Going the full drop-top experience will ruffle more than hairdos at freeway speeds, though. An optional wind deflector can fix that issue for front-seat occupants, but it goes over the back seats, turning the M4 into a two-seater ragtop.

Further back, the 300-litre boot isn’t accessible from the cabin, meaning you can’t put much inside at all. BMW fits a hinged flap that needs to be down for the roof to work since it cordons off the roof storage part of the boot when folded in; when lifted, there’s a useful amount of space for luggage, and it’s a handy rectangular shape instead of an L-shaped slot, but obviously at the cost of convertible driving. You can’t have both.

Note that, compared to the previous folding-hardtop M4, this boot is some 80L larger. 

At just under 4.4m long, close to 1.8m wide and little over 1.5m tall (with a 2655mm wheelbase) the CX-30 is in the middle of the pack it competes with in terms of key dimensions.

And space up front is more than adequate, with an impressive feeling of roominess for a relatively small SUV.

For storage, there’s a large lidded box (which doubles as an armrest) between the front seats as well as a pair of cupholders in front of the gear-shifter with a bay for wireless device charging ahead of that.

The glove box is big, there are bins in the doors with room for decent size bottles and a drop-down tray for sunglasses sits overhead.

Move to the rear and the amount of space on offer is surprisingly generous. Sitting behind the driver’s seat, set for my 183cm position, I have plenty of head and legroom, although three full-size adults across the back seat will be an uncomfortable proposition for anything other than short trips. A trio of up to mid-teenage kids will be fine.

Adjustable air vents at the back of the front centre console are a welcome inclusion for back-seaters and storage runs to a map pocket (weirdly, on the back of the front seat only), a pair of cupholders in the fold-down centre armrest and bins in the doors with room for smaller bottles.

In-cabin power and connectivity includes two USB-C outlets and a 12-volt socket in the front centre storage box. No USBs specifically for those in the rear, which is a miss for road trips and no 12V in the boot which can be handy when camping or picnicking.  

Speaking of the boot, cargo volume with the rear seat upright is okay for the class at 317 litres, which expands to a healthy 1479L with the 60/40 split-folding backrest lowered. For comparison the Kia Seltos coughs up 433L with the rear seat upright.

The space is illuminated, there are tie-down anchors to help secure loose loads and there’s a space-saver spare sitting under the floor.

And if you’re keen on towing a tinnie or similar you’re good to go for a 1200kg braked trailer (600kg unbraked).

The Mazda CX-30 G25 GT SP FWD weighs in at $43,140, before on-road costs and our test example features the optional ‘Vision Pack’, the details of which we’ll get to shortly, raising the price $1300 to $44,440. 

Alternate options around that price point include the Hyundai Kona Premium N Line 2WD ($42,500), Kia Seltos GT-Line FWD ($41,850), Mitsubishi Eclipse Cross Exceed 2WD ($40,990), Honda HR-V e:HEV L 2WD ($42,900, drive-away), Nissan Qashqai ST-L FWD ($42,690), Peugeot 2008 GT FWD ($44,490), Renault Arkana Techno FWD ($41,000), Suzuki S-Cross Plus FWD ($41,490), Toyota C-HR 2WD GXL Hybrid ($42,990) and Volkswagen T-Roc Style FWD ($40,590).

That’s quite the automotive smorgasbord, the resulting price and specification cage fight meaning every included feature counts and the Mazda heads into battle with some significant weapons in hand.

Specifically, dual-zone climate control, a head-up display, a 10.25-inch ‘widescreen’ multimedia display, 7.0-inch driver’s multi-information display, 12-speaker Bose audio (with digital radio), wireless Android Auto and Apple CarPlay, ‘Burgundy’ leather seat trim, heated front seats, leather trim on the gearshift and heated steering wheel, wireless phone charging, power-adjustable driver’s seat (with memories), a glass power tilt and slide sunroof and a power tailgate.   

There’s also adaptive auto LED headlights, 18-inch black metallic alloy wheels, radar cruise control (with stop/go), a reversing camera, auto-fold (and tilt) heated exterior mirrors and keyless entry and start. 

It’s an impressive and competitive equipment list for a small SUV under $45K, even before we get to the performance and safety tech covered later in the review.

Here is a summary of Australian-market outputs and prices for the M3 and M4 convertible autos, with the prices in brackets being approximate inflation-adjusted figures for today.

1999 E36: 236kW/350Nm 3.2L in-line six-cylinder engine (I6), $152,000 ($266,000 in 2022); 2003 E46: 252kW/365Nm 3.2L I6, $158,000 ($240,000); 2008 E93: 309kW/400Nm 4.0L V8, $183,442 ($240,000); 2014 F83: 317kW/550Nm 3.0L twin-turbo I6, $178,430 ($202,000).  

In 2022, the G83 M4 Competition lives up to its name in more ways than one, with a 2993cc 3.0-litre double overhead cam direct-injection twin-turbo I6 known as the S58 series, which is itself derived from BMW’s B58 modular family of engines. Its 375kW is delivered at a lofty 6250rpm, while there’s a 650Nm plateau of torque between 2750rpm and 5500rpm.

A kerb weight of 1920kg means the M4’s power to weight ratio is an impressive 195.3kW/tonne, helping its published 0-100km/h time of 3.7s. For a few grand extra, the company will up the top speed by 30km/h, to 280km/h.

BMW says the engine includes cooling and oil supply systems designed for extreme lateral forces at high speeds, while the exhaust uses electrically controlled flaps for a more raucous noise.

Power is channelled to all four wheels continuously via an eight-speed M Steptronic transmission with a trio of shift programs. The AWD system features an active differential to better transmit torque to all four wheels, while drivers can choose one of three, progressively more rear-wheel drive (RWD) biased modes: 4WD, 4WD Sport and 2WD – the latter being a pure RWD set-up.

Other related changes the M4 boasts over regular 4 Series models include special stability and traction control tuning, a double-joint spring strut front axle with unique axle geometry and variable-ratio steering, a five-link rear axle featuring its own kinematics and elastokinematics, M-specific adaptive dampers, a configurable braking set-up according to feel and response, and forged M light-alloy 19-inch alloys up front and 20-inch items out back.

Choosing the AWD-only convertible over the equivalent AWD coupe adds 145kg (and 195kg compared to the RWD coupe), though this is partly offset in two ways over the preceding, folding-hardtop M4 Convertible: firstly, using the soft top drops weight by 80kg; and secondly, while the AWD system does add 50kg, it’s at a lower centre of gravity, thus naturally improving vehicle dynamics.

Which are electrifying, by the way.

The CX-30 GT SP is powered by a 2.5-litre, naturally aspirated, four-cylinder petrol engine producing maximum power of 139kW at 6000rpm and peak torque of 252Nm at 4000rpm.

It’s a proven all-alloy unit featuring direct-injection as well as variable intake and exhaust valve timing with drive going to the front wheels via a six-speed auto transmission. 

The AWD version of the GT SP adds an electromagnetic multi-plate clutch pack (managed by a multitude of sensors) to selectively engage the rear wheels, as well. But its engine and transmission combination is identical to this FWD model’s.

We managed 12.1 litres per 100km in a mixture of urban, freeway and rural-road driving, including plenty of performance testing. This is a two-tonne M4 convertible capable of supercar speeds, after all. In that context, the economy is more than acceptable. No doubt the stop/start engine function (at idle) helps here.

For the record, the official combined-average claim for this Euro 6-rated BMW is 10.4L/100km, for a carbon dioxide emissions average of 237 grams/km. Thanks to a fuel tank that holds 59 litres of 98 RON premium unleaded petrol, it can manage an average of almost 570km between refills.

The CX-30 GT SP FWD’s official fuel consumption figure on the combined (urban/extra-urban) cycle is 6.6L/100km, the 2.5-litre atmo four-cylinder engine emitting 154g/km of C02 in the process.

It features fuel-saving stop-start and cylinder deactivation functions as standard and over a combination of city, suburban and some freeway running we saw an average of 8.4L/100km, which is average for an SUV in this class. A comparable hybrid package would easily better this result.

Based on the car’s 51-litre fuel tank theoretical range between refills is 772km, which drops to just over 600km using our real-world test consumption number. But the good news is this CX-30 runs happily on cheaper 91 RON ‘standard’ fuel.

Marvellously.

Earlier, we said that the previous M4 (and some earlier M3 generations) never hit the dizzy heights the best like the E46 managed.

The reason why is bandwidth. Not WiFi bandwidth, but rather the newfound breadth of capability that the G83 model has acquired.

Yes, while even the slowest examples of previous M3s and M4s remained thrilling, with blisteringly potent acceleration accompanied by a soaring exhaust soundtrack, the post-E46 models seemed to become almost too obsessed with the pursuit of performance. Thunderous V8s and twin-turbo V6s are all good and well, especially when they provide explosive responses, but there’s more to sports cars than sheer bloody-minded speed.

More specifically, though the handling and roadholding were outstanding, the previous M4’s steering didn’t feel as connected or one with the driver, instead seeming a little remote and detached. Conversely, even with adaptive dampers on offer, the suspension (on Australian roads) lacked sufficient isolation from bumps and thumps, and so was never settled or calm. It was all too nervous and edgy, like a drug-addled athlete who’s indulged in too much partying.

Thankfully, the curse is broken with the latest iteration, even in the heaviest and slowest version like our M4 Convertible as tested, pushing out boundaries to thrilling effect once more.

With the newly-simplified and logically presented M performance modes only a push of a button away, the driver now no-longer has to concentrate on what setting they’re in, and instead just immerse themselves in the experience of accelerating, steering, cornering, braking and controlling this incredible sports convertible.

Tremendously strong in regular Road mode, the M4’s performance certainly lives up to the legend, stepping up into the supercar realm when Sport or Track are chosen, hunkering down as it thrusts towards the horizon with relentless speed and determination, accompanied by the gorgeous twin-turbo six’s revs as they soar towards the red line. The ultra-alert eight-speed auto’s operation is equally seamless, displaying uncanny intuition in its selection of the right ratio at exactly the right time.

These are all incremental improvements over what has come before. But what’s really changed is how rock-solid the BMW feels as it belts along at speed, magnetised to the motorway regardless of weather, its new AWD engineering keeping everything steady and planted. No more tetchiness to unnerve the driver.

Which makes the feel and fluency of the chassis even more remarkable, given that now all four wheels are driven. The very opposite of leaden or inert, the superbly weighted steering is instead light and alive in your palms, as you carve through corners with pin-point precision. Some might find it a bit too eager to change direction at first, but we reckon BMW has judged the balance just right. Its sheer agility is as life-affirming for driving enthusiasts as it is immersive. Bravo, BMW.

With so much grip and control, this is not to say that the driver can’t hang the M4’s tail out every-which-way, since the chassis set-up allows for progressive oversteer, even in Road mode, along with as much drifting as your courage allows where safe. As with the best sports cars, the M4 is as steerable from the seat of your pants as it is using the throttle.

Finally, there’s the M Adaptive chassis tune, that at long last broadens the M4’s repertoire from motorway grand tourer and rural-road blaster to city slicker and urban warrior, thanks to the suspension’s ability to better-absorb a much wider array of terrible road surfaces. Comfort now lives up to its name, with the ride – though still firm – no longer hard or crashy around town, ushering in a new level of civility that won’t fatigue or aggravate you or your occupants. We're so happy to report this progress.

One area where BMW might want to keep improving, though, is the abundance of road noise intrusion over certain coarse chip bitumen. While easily muffled by the sweet sounds of the twin-turbo six, banging audio system or dropping the roof, it now seems more obvious that the rest of the car has smartened up so much.

A small fly in an otherwise hugely satisfying ointment.

It’s rare in 2024 to find a small SUV that doesn’t have at least one turbocharger attached to its engine, the CX-30’s 2.5-litre ‘atmo’ four being one of those increasingly scarce examples.

But Mazda’s been laser-focused on extracting maximum power and efficiency from its non-turbo petrol engines for yonks and this one stands up well.

It doesn’t have the low-down punch a turbo typically delivers but maximum pulling power arrives at a useable 4000rpm and it’s eager enough for easy city and suburban running as well as confident freeway cruising.

Although Mazda doesn’t quote an official number you can expect a sprint from 0-100km/h in around 8.5 seconds, which is quick for the class.

Worth noting engine noise and a raspy exhaust note make their presence felt under acceleration and the throttle isn’t as refined as it could be. Not a huge deal, but a slight jerkiness is evident on initial, especially moderate, acceleration.

The six-speed auto is smooth and fuss-free, the steering wheel paddle shifters on hand if you need to intervene and select a specific ratio. ‘Sport’ mode peps things up, causing the transmission to shift down earlier and up later. But it’s aggressive in that it often holds onto a gear for too long and you find yourself diving back to the default normal setting.

Tipping the scales at just under 1.5 tonnes, the CX-30 is underpinned by a MacPherson strut front, torsion beam rear suspension and ride comfort on typically pock-marked urban surfaces is average for the category. That is, a bit jittery over bumps and corrugations but there’s no bone-jarring going on here.

Steering feel and response is good and the grippy steering wheel helps with a connection to the front tyres. Speaking of which, the standard rubber is high-performance (215/55) Dunlop SP Sport Maxx 050 which is  grippy and commendably quiet. 

Push on into a corner and the CX-30 remains balanced and predictable with body roll well under control. Torque vectoring, by engine and physical braking, is also onboard to reel things in if you overstep the mark.

Braking is by discs all around, vented at the front and solid at the rear, and they wash off speed effectively with a satisfyingly progressive pedal action.

Vision is good, which combined with the CX-30’s compact dimensions and 10.6m turning circle, means parking is easy. Especially when you factor in the hi-res reversing camera and front and rear parking sensors. 

The CX-30 carries a maximum five-star ANCAP assessment from early 2020 when the car was introduced locally.

It scored a stunning 99 per cent in the adult occupant protection category and an impressive 88 per cent for child occupant protection.

Active (crash-avoidance) tech includes AEB (operating from 4.0-160km/h) as well as lane keep assist, lane departure warning, traffic sign recognition, intelligent speed assistance, blind-spot monitoring, front and rear parking sensors, rear cross-traffic alert, a reversing camera and tyre pressure monitoring.

Mazda’s ‘Vision Pack’ is also standard which includes a 360-degree camera view, ‘Cruising & Traffic Support’, driver fatigue monitoring and front cross-traffic alert.

The airbag count runs to seven - dual front and front side, full-length side curtains and driver’s knee.

There are three top tether points for child seats across the second row with ISOFIX anchors on the two outer positions.

We feel here is where the company drops the ball.

Trailing all of its main luxury car rivals (except Porsche) by two years, BMW only offers a three-year/unlimited kilometre warranty, as well as three years of roadside assistance.

BMW says its vehicles’ servicing is condition-based, depending on how they’re driven and other factors, with a dash warning appearing to let the driver/owner know when it’s time. We advise servicing your M4 annually or at every 10,000km, just to be sure.

No capped-price servicing system is offered. However, as long as the first one is paid for before the first service on a new vehicle, the ‘BMW Service Inclusive Basic packages’ is available at extra cost, covering scheduled servicing for three years/40,000km or five years/80,000km.

No prices are published for M models like the M4, but a normal 4 Series costs from $1800 for the five-year/80.000km package. You can bet an M4’s will cost more.

Mazda covers the CX-30 with a five-year/unlimited km warranty which is the norm in the mainstream market, and it’s worth noting a growing number of competitors are now at six, seven or even 10 years, although the latter are typically conditional on authorised dealer servicing. Roadside assistance is provided for the duration of the warranty.

Service is recommended every 12 months or 15,000km and Mazda’s ‘Service Select’ program sets maintenance pricing out to seven years, the lowest over that period being $352 and the highest $626, for an annual average of $459, which is reasonable but not exceptional for the category.

For comparison, a similarly specified Toyota C-HR averages $330 per workshop visit over the same period.