BMW X3 vs BMW M4

What's the difference?

This is a highly competent all-rounder, given that it has the comfort and practicality for urban family duties yet with its revered M breeding can produce a level of performance which, in competent hands, could hold its own at a track day where its capabilities could be safely explored.

Brutal, bruising and utterly brilliant, the M4 CS will be an acquired taste due to its no-compromise approach, but those willing to take the leap will find a performance car like few others at their disposal.

The fourth-gen X3, which has a lighter but stiffer body, shares the same wheelbase as its third-gen predecessor but at 4755mm end-to-end it's 34mm longer and it's 29mm wider.

It’s also 25mm lower, which combined with front and rear track-width increases and adaptive suspension damping to sharpen the handling underlines its sportiness and driver appeal, despite a substantial 2055kg kerb weight.

The new exterior design is characterised by short overhangs, flush door handles, a larger ‘split kidney’ grille, new LED taillights and L-shaped light elements for the LED headlights.

The new interior design is a classy mix of soft-touch materials and high-gloss hard surfaces in tastefully contrasting tones. The seats are upholstered in a new synthetic leather called 'Veganza' ('Espresso Brown' in our example) which according to BMW requires 85 per cent fewer CO2 emissions to produce than genuine leather (which is still available as an extra-cost option).

Combined with subtle use of ‘Magnolia’ fine-wood trim inserts, satin chrome, piano black, blue/red M highlights and slender ambient light-strips, it’s a cabin that exudes opulence.

The M4 CS is familiar in all the right ways, but definitely looks significantly jacked up compared to its lesser siblings.

Part of that is the extensive use of carbon everywhere, from its bonnet panels to its roof, front lip, side skirting and boot spoiler. But also because of its super-muscular angles and creases, including the huge dome in its bonnet.

Also exclusive to this M4 CS is the light treatment, with the front LEDs lighting up with yellow highlights the brand says are supposed to be reminiscent of GT racing cars.

At the back, the rear lights are flush with fibre optic lighting, lending a flowing and unique light signature that looks epic at night.

Inside, it's a sea of carbon, with the lightweight racing seats, the dash inserts and the centre console all lined in it. It is a perfectly finished space, though, and one that's also flecked with red, including a 12 o'clock band on the thick-rimmed steering wheel, the seat backs, the contrast stitching and the paddle shifts.

Be warned, though, it takes some acrobatics to climb into or out of the CS. The seat bottoms have these super high edges that double as grab handles, but require some awkward contortions to navigate.

In short, it looks angry, this M4 CS, inside and out.

This would make a great family weekend escape machine, for which BMW quotes a 645kg payload rating. It’s also rated to tow up to 2500kg of braked trailer, which could pose a challenge given the relatively low 100kg tow-ball download limit (TBD is typically around 10 per cent of trailer weight).

BMW also does not publish a GCM figure (how much it can legally carry and tow at the same time) so we can’t confirm if it can carry its maximum payload while towing its maximum trailer weight.

Even so, the M50 has a useful-sized luggage area which offers up to 570 litres (or 0.57 cubic metres) of load volume with the rear seat upright.

This expands to 1700 litres (or 1.7 cubic metres) with the rear seat folded flat, which can be handy for a multitude of tasks like transporting a mountain bike or hauling home flat-pack furniture.

There’s comfortable space for the driver and front passenger, along with useful storage including large bottle-holders and bins in each front door.

The centre console has two small-bottle/cupholders plus wireless phone-charging and a pair of USB ports. There's also a glove box plus another box at the rear of the console with a padded lid that doubles as an elbow rest.

The rear bench seat is surprisingly spacious, given that I’m 186cm tall and when seated behind the driver’s seat in my position I still have about 40mm of knee clearance, which is optimised by the concave shape of the front seat backrests.

The spacious and airy feel is enhanced by the ‘panorama’ glass roof which spans the full length of the seating area and allows generous headroom even for tall people.  

However, shoulder room is tight for three adults and the centre passenger’s feet must contend with the transmission tunnel, so even though it would be fine for three kids we’d suggest a limit of two adults for longer trips.

Rear passengers get privacy glass and pull-up roller sunshades, large-bottle holders and bins in each door plus net-type pockets and anchorage points for media devices on each front seat backrest. There are also two small-bottle/cupholders in the fold-down centre armrest.

The rear of the centre console has two USB ports, adjustable air-vents plus controls for zone temperature, airflow preferences and seat-heating.

The bench seat features a 40/20/40 split, which allows the centre backrest to fold forward independent of the two outer backrests to allow long loads like snow skis, home hardware etc to be carried if securely fastened.

A power tailgate provides access to the luggage area, which is equipped with a handy 12-volt accessory socket plus load-anchorage points front and rear, extra storage nooks for small items on either side and a retractable roller-type load cover. Overall, this vehicle offers good practicality for family duties.

It all boils down to how you classify practicality in a car like this. I mean, the basic stuff is all there – it's got two doors, four seats and a boot capacity of 440 litres.

It measures 4801mm in length, 1918mm in width and 1399mm in height, and room for front seat riders is good, but less so for anyone you squeeze into the back. There are even ISOFIX points for a child seat.

But if you consider practicality the practical pursuit of performance, then the M4 CS has plenty of perks.

We're talking a $254,900 entry price for the M4 CS, which – despite my attempts at justification – is a lot. Remember, the regular M4 is $168,700, and the M4 Competition is $186,500, so we're talking a sizeable premium here.

BMW justifies that price increase in two ways. The first is scarcity, with the M4 CS limited to just 50 examples in Australia. And the second is by dialling up every aspect of the M4's performance to terrifying levels.

The engine outputs are up, the weight is 20kg down, there are better brakes, better seats, a louder exhaust, a stiffer chassis – it goes on and on.

We'll get to some of the performance stuff in a moment, but here's what else your money buys you with the M4 CS.

It starts outside with staggered alloys, 19-inch up front and 20-inch at the rear, wrapped in track-ready rubber. There's also hi-po 'M Compound' brakes with red calipers, lightweight carbon racing seats that are heated up front, an Alcantara-trimmed steering wheel, the 'M Carbon' exterior package with carbon bonnet and roof, adaptive 'M Suspension' and a titanium exhaust that howls like the winds of hell.

The less performance-focused stuff is similar enough to the other M4 models including a 12.3-inch centre screen with digital radio, Apple CarPlay and Android Auto, a second 14.9-inch screen that handles your driving data and a head-up display. There's also twin-zone climate control, Merino leather upholstery and ambient interior lighting.

But all of that is secondary, really. This is about performance, specifically of the brutal kind.

According to BMW, the M50 xDrive features the most powerful inline six-cylinder petrol engine fitted to an M Performance model.

This 3.0-litre unit clearly benefits from BMW’s twin-scroll turbocharging technology, which combined with variable valve timing and an extra 13kW/200Nm from the 48V mild-hybrid technology produces a stomping 293kW of power at 5500rpm and 580Nm of torque at 1900rpm.

It also has a ‘boost’ function, which provides an extra burst of power for short periods when maximum acceleration is required when overtaking etc.

It’s activated by the left paddle-shifter on the steering wheel and automatically optimises transmission/chassis settings to suit. There’s also a drive mode selector, with ‘Sport’ offering the most responsive and engaging experience.

The eight-speed torque converter automatic is a refined and efficient transmission well suited to this full-time all-wheel drive application. Rapid-fire manual shifting is also available using the steering wheel paddles.

BMW has found yet more grunt lurking in its trusty 3.0-litre 'M TwinPower' six-cylinder petrol engine, with the M4 CS now pumping out 405kW and 650Nm.

That's a decent jump from the 390kW and 620Nm served up by the M4 Competition, and a giant leap from the outputs of the 'base' M4 – 353kW and 550Nm.

Predictably, then, the CS is the fastest of the lot, knocking off the run from 0-100km/h in 3.4 seconds, compared to 3.5 and 4.2 in the Competition and M4, respectively. The top speed is also dialled up to 302km/h.

All that power is channeled through an eight-speed automatic and sent to all four wheels on demand, with the help of an 'Active M Differential'.

BMW claims an official average combined consumption of 8.2L/100km but the dash display was showing 9.9 at the completion of our 210km test, which included a mix of suburban, city and highway travel.

Our own figure, calculated from fuel bowser and tripmeter readings, came in slightly higher again at 10.5L/100km, which given our test vehicle’s two-tonne-plus weight and performance capabilities is still reasonable economy.

So, based on our figures, you could expect a realistic driving range of around 600km from its 65-litre tank, which prefers premium 98 RON petrol.

The M4 CS is fitted with a 59-litre fuel tank, which – given the BMW's official fuel claim of 10.2 litres per hundred kilometres – should deliver a driving range on a full tank of 541 kilometres.

But... BMW also says the regular M4 – you know, the one that makes 52 fewer kilowatts and 55Nm less torque – uses 10.1L/100km, so do with that information what you will.

First, the fun stuff. It certainly feels like ‘the ultimate driving machine’ when you slide behind the chunky leather-rimmed flat-bottom steering wheel and hold it in your hands.

The driver’s seat offers not only powered adjustment of backrest and base-cushion rake, but also four-way lumbar support and side-bolsters that can tighten their embrace of your upper torso to contend with high cornering loads.

There’s also manual extension of the base-cushion length for greater thigh support and a big left footrest to brace against, so you could not ask for a more accommodating and purposeful driving position.

The steering is perfectly weighted and the quartet of enormous disc brakes provide ample bite with superb pedal feel. Combined with its adaptive suspension and wide grippy tyres, the X3 is a family car that’s also invigorating to drive, particularly when you select the ‘Sport’ mode.

The enhanced engine response and sharper steering that result (even the instrument panel display changes) make any twisting mountain road an engaging experience, enhanced by an intoxicating exhaust note that only a BMW M six can deliver.

The turbocharged engine offers an unyielding surge of acceleration from well below peak torque at 1900rpm to maximum power at 5500rpm, making BMW’s claim of 0-100km/h in a scant 4.6 seconds sound credible.

You can also manually change gears using the steering wheel paddles, but we found the gearing and shift calibrations so good that we preferred to leave it in auto mode.

However, the X3 M50 has two distinct personalities, as in more relaxed drive modes it’s just as happy serving as practical family transport during the week for grocery shopping, daily school runs and other common tasks.

It’s also a comfortable tourer for family getaways, with long gearing that requires only 1500rpm to cruise at 100km/h where low engine, tyre and wind noise allow highway conversations at lounge room levels.

The hardest and angriest M4 of all time is, perhaps unsurprisingly, hard and angry. This is a race track specialist, but because I don't happen to own one of those, my first experience with the barking (and barking mad) M4 CS was navigating my way back from BMW's inner-city dealership.

Like it or lump it, you're going to read some Porsche comparisons here, because you're talking not too far off base 911 Carrera money, and suddenly I find the two Germans doing battle for a spot in my dream garage.

First things first, the BMW won't be much chop for daily driving for most people. Happily, I have a sickness for uncomfortable sports cars. It tells me that no compromises have been made in the pursuit of punishing performance.

A good thing, too, because the BMW, at city speeds, can be punishing. Everything feels heavy, the seats aren't overly comfortable – especially the hard bits that tend to dig in when cornering – and it stiff-arms its way over road imperfections, that exhaust booming and barking as it does.

Again, I loved it, and you probably will, too. But it's still not the kind of car I'd relish sitting in the morning peak hour rush in.

But escape the confines of the city and the BMW M4 CS suddenly makes a whole heap of sense. The acceleration is genuinely brutal, and wonderfully theatrical, with that quad-tipped titanium exhaust barking and snarling as you rocket towards 100km/h.

The steering is brilliant, with feedback fed to your wrists via that thick-rimmed wheel, and the entire experience feels sharp, super engaging and edgy.

You can push the M4 hard and fast, and I'm certain my limited talents would run out far before the BMW's would, but there's this thrilling sense of peril sparked by the aggression of the experience, that I love.

It's like the magic of a roller-coaster, I guess. Even if you know nothing is going to happen, you never really know, right? And in that lies the magic.

But back to original question, this or a Porsche 911? There's no doubt a Carrera is a better all-rounder, in terms of comfy commuting and race track fun, but this angry M4 is all shouty theatrics, all of the time.

I bloody love it.

Expect no ANCAP rating here, I'm afraid. But the BMW 4 Series does wear a five-star rating from 2019.

The M4 CS gets six airbags (driver and passenger, side airbags, head airbags), along with what BMW calls its 'Driving Assistant Professional', which bundles active cruise control (with stop and go function), front and rear cross-traffic warning, 'Steering & Lane Control' and 'Lane Keeping with Side Collision Warning'.

It comes standard with a five-year, unlimited km warranty.

Scheduled servicing is determined by BMW’s vehicle monitoring system which advises when a service is needed, typically around 12 months/15,000km.

A capped-price servicing package covering five years/80,000km (whichever occurs first) totals $2475, or an average of $495 per service.

The M4 CS is covered by BMW's five-year, unlimited-kilometre warranty, with condition-based servicing available in packs, which will cost you $3530 over five years/80,000km, or $2900 over four years/60,000km.