BMW i Series vs BMW M4

What's the difference?

The BMW iX3 is a rarity in the market, a premium-feeling electric model that's not a whole lot dearer than petrol alternatives.

For those happy to trade some of the Tesla Model 3 and Kia EV6 GT's all-paw performance for a luxurious cabin, slick drive and badge cachet, the iX3 M Sport is a very attractive package. Until Audi's Q4 and Q6 e-tron arrive, the iX3 remains basically peerless in this part of the market.

No wonder, then, that BMW is Australia's third most popular electric car brand after Tesla and BYD. The vehicles capture everything the brand promises at a price that looks good on paper and better in the real world.

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.

Now that we've seen the new X3, the current model is already dated. Not that it was a cutting-edge design at launch but there is precious little offensive about this mid-size SUV.

Fussy wheel designs, strange closed in grilles and clashing blue accents aside the iX3 M Sport remains a plenty handsome option as you approach.

Inside the cabin's shapes feel positively conservative next to BMW's latest efforts like the X2 and 7 Series but, in a way, this is no bad thing.

It's also nice that you can tailor this car's appearance to your liking without spending extra, the combination here rocks a nice blue paint with tasteful brown upholstery for a classy look.

You can have Oyster white leather or simple black and the paint colour palette is refined without being restrictive.

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.

The BMW X3 was developed with family buyers in mind and that has paid dividends because it has an extremely practical cabin with lots of thoughtful storage.

Each of the four doors has a bottle holder and generously-sized pocked for extra storage. There are two cup-holders in the centre with a wireless charging pad, secure spot for the key fob and USB port in easy reach. You can slide a roller cover down to hide valuables.

Key driving controls are smartly grouped together around the iX3's unconventional gear selector. Here, you'll find the start/stop button along with hard switches for drive mode selection, stability control and exterior cameras.

Right next door is where the rotary 'iDrive' controller lives with yet more physical shortcut buttons. Including the extra option to easily interact with the multimedia system on the move is a refreshing delight that you don't see in so many touchscreen-heavy EVs. There's also a physical stack for HVAC and seat heating controls.

The 12.3-inch touchscreen is responsive and bright with BMW's slightly older system having a more conventional appearance than the latest software in the iX2. Apple CarPlay and Android Auto are wireless and still work flawlessly.

If there are some negatives, they would be some build-quality niggles. On the whole the materials are high quality and the car is well screwed together but the indicator stalks feel decidedly flimsy compared to BMWs of old and I noticed a rattle from the parcel shelf on the road.

The eight-way power adjust seats with tilt and under-leg extension are classic BMW, being sporty enough to hold you in but with enough padding to stay comfy. Though we will knock this car down for lacking power lumbar adjust.

Those in the back will be plenty comfortable even if they're taller than 180cm with ample head, leg and toe-room. There doesn't appear to be a major compromise to the floor height despite BMW stacking 10 lithium-ion modules beneath.

Vision out is excellent with an expansive glasshouse and full-length sunroof.

Amenities include two USB-C charge points, a third climate zone, fold-out armrest with pop-up cup holders and generous storage in the doors.

Fitting child seats should be pretty simple with doors that open wide, two sets of ISOFIX ports (that you can't lose the covers of) and three prominent top tether anchors in the recline-adjustable backrest.

The boot is large with 510L of space at a minimum that expands to 1560L if you fold the 40/20/40 split backrest flat. There's a sense of solidity in that process, too, with sturdy levers and components.

So sturdy that the retractable luggage cover is quite difficult to remove, especially for shorter owners. Other niceties include a single shopping bag hook, LED lighting and 12-volt socket in the back.

No BMW X3 comes with a spare tyre so that should come as no surprise. The iX3 instead has a tyre repair kit. There is underfloor storage in the iX3, though, which is the perfect place to store both charging cables — Mode 2 and 3 — that are included.

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.

In this case there isn't much under the bonnet except for electric gubbins. The single electric motor – that uses no rare earth materials – resides at the back and generates 210kW/400Nm.

Those outputs are fairly close to a petrol X3 30i, though of course this model is rear-drive only.

Thanks to the rapid response of electric motors, the iX3 M Sport can sprint from 0-100km/h in 6.8 seconds (claimed).

BMW has chosen to give the iX3 a long-travel progressive throttle pedal that makes grunt easy to meter out. However, the regenerative braking could do with a little more refinement.

There are two settings, 'D' — just like letting off the throttle in a combustion car — and 'B' which is quite strong. The blending between regenerative and physical caliper-on-rotor braking is vague, though, which can make low-speed moves a bit jerky.

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'.

The iX3 M Sport's WLTP rating is a respectable but not groundbreaking 461km on the combined cycle. The reality is a little bleaker, our test car displaying 316km on its digital instruments at 100 per cent charge.

Going against what you might expect for an electric car, the iX3 was not very efficient in town, we initially saw 24kWh/100km on the read-out which is quite high.

It is better suited to a longer, steady-state run. Our regular 200km country and suburban test loop dropped the consumption to 18kWh/100km for a real-world driving range of 411km.

When it's time to bring the charge levels back up the iX3 will take on AC electricity at 11kW, for flat to full in seven and a half hours.

Public fast-charging caps out at 150kW (DC) though averages to 104kW over a 10-80 per cent session. This should take 21 minutes, says BMW.

We only observed a maximum of 101kW on a DC charger though the pylon did not appear to be performing at full energy with other vehicles having similar issues.

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.

Despite no saucy straight-six, V8 or twin-cam four-cylinder there is an inherent 'BMW-ness' in the iX3 M Sport. The way it steers, accelerates and rides all match the brand's DNA.

It is not a plush SUV, with some firmness to the suspension even in Comfort mode on the adaptive dampers — this may have something to do with BMW's 40PSI front and 45PSI rear tyre pressure recommendations — but without ever being crashy.

Build up a little more speed, beyond 60km/h for example, and the body settles nicely with a solid, assured stance.

There's no evidence of suspension noise and road noise is very well insulated as well, even without the up-spec M Sport Pro's acoustically insulated glass. 

The steering is light in Comfort mode which makes it ideal for urban driving. It also has three turns lock-to-lock which is a lot for a sporty-ish BMW, however that is largely down to the improved steering angle. Without an engine or AWD system, the iX3 has a great turning circle of just 12.1 metres.

Moving things up a notch into Sport adds extra weight to the steering which helps judge the grip on good roads, which is pretty decent from the 245/45R19 Yokohama Advan Sport V107 tyres.

When you approach the limit, the iX3 is very secure but significant mid-corner bumps can unsettle the car, bringing its 2180kg tare weight (a 325kg penalty over the xDrive20i) sharply into focus. Pull it back a touch, though, and the iX3 M Sport is plenty rewarding on a country road.

Mostly, the iX3 is a refreshingly natural electric car out on the road. You could put anyone in the driver's seat and they'd be smooth just like in a combustion car.

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'.

The iX3 M Sport is now covered by a five-year/unlimited kilometre warranty in Australia.

Servicing is due on a conditional basis with the multimedia system prompting the owner when to visit a dealer.

BMW offers serviced packages for electric vehicles that last six years/unlimited kilometres, with the iX3's pack costing a reasonable $2325 over that time.

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.