BMW 428i vs BMW M Models

What's the difference?

The 4 Series line offers three distinct points of difference from the more traditional 3 Series, each with their own attraction. The sharpening of the sticker prices and the additional spec helps their cause as well, with the 430i Coupe probably our pick of the range. The 440i is the firecracker of the group, while the 420d is also worth a look, thanks to its value and prodigious torque output.

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.

No external changes to the 4 Series' bodywork have been affected  for  this midlife refresh, but there have been plenty of tweaks to the standard equipment offerings right across the board.

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.

Two-doors are never the most practical devices, but the 4 Series Coupe and Convertible duo make a decent fist of it for front-seat passengers. There are bottle holders in both doors and a pair of cupholders in the centre console, along with a large lockable glovebox.

The centre bin is, however, quite shallow, and houses the car's single USB port inside it. There is covered storage under the dash for smaller items, and a small rubber-lined tray that the current crop of phones has outgrown.

The rear seating in the Coupe is reduced to almost a formality, especially if the front seat passengers are tall and the front seats are set back, while the sloping roofline reduces head space quite considerably. A centre armrest contains a pair of cupholders, and there are small side pockets.

Rainy conditions precluded us from trying the Convertible's metal folding roof, but the rear seat space restrictions also apply here. Its 370 litres of boot space is roomy enough for a drop-top, while a clever lifting function raises the folding roof structure up by about 300mm to allow luggage to be stowed under the panels when the roof is down. Capacity drops, though, to just 230 litres.

The Gran Coupe, on the other hand, is the most practical car in the entire 3 and 4 Series line-up outside of the 3 Series Touring wagon. With a large, flat load area, and a hatch-like tailgate, the Gran Coupe can swallow 480 litres of gear with the seats up and an impressive 1300 litres with the seats lowered.

Face-level rear vents, more head and backseat legroom – not to mention the fact you don't have to squeeze into the rear past the front seat – makes the Gran Coupe a most useful device, and it's little wonder it's the most popular variant of the three.

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.

There are two new petrol engines, two new badges and prices cuts of up to $10,000 right across the board for the line-up, along with additional standard equipment that improves the value equation even further.

The line kicks off with the 420, which can be had in either diesel or petrol guise. The 420i gains BMW's new B48 2.0-litre four-cylinder turbo petrol engine, which gains 5kW over the old motor to produce 135kW and 270Nm.

It also benefits from slightly improved fuel economy, with a drop of 0.3 litres per 100km for the Coupe and 0.5 for the Gran Coupe to 5.8L/100km, and a fall of 0.2L for the Convertible to 6.2L/100km.

The 420d retains its 140kW, 400Nm 2.0-litre four-cylinder turbo diesel engine, which returns 4.3L/100km in the fixed roof cars and 4.7L/100km for the Convertible.

The 430i – formerly known as the 428i – also receives the new 2.0-litre petrol engine, albeit in a 185kW/350Nm tune. Its fuel economy drops a healthy 0.6L for the Coupe and Gran Coupe and 0.4L for the Convertible, posting figures of 5.8 and 6.3L/100km respectively.

The top-spec 435i has been transformed into the 440i with the addition of BMW's new Twinpower 3.0-litre straight six petrol motor. Its output jumps 15kW to 240kW and by 50Nm to 450Nm, and its consumption falls by more than half a litre to 6.8 litres per 100km for the closed-roof pair and 7.2L/100km for the Convertible.

All cars come standard with a 'traditional' ZF eight-speed torque converter automatic transmission with steering wheel paddles as standard fitment, while a six-speed manual gearbox is a no-cost option across the line.

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'.

Our brief test loop on a rainy, blustery Melbourne winter's day in all three model types (but no diesel) netted varying fuel consumption readings across the line; we recorded 8.4L/100km in a 420i sedan against a claimed figure of 5.8, 9.8L/100km for the 430i Gran Coupe against a claimed figure of 5.8L/100km, and 8.4L/100km against the 440i Gran Coupe's 6.8L/100km.

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.

BMW introduced a raft of tweaks to the 3 Series platform late last year, which have translated over to the 4 Series. The key addition across the line is BMW's two-stage adaptive dampers that feature a Sport and a Comfort circuit, fitted as part of the M Sport pack that comes standard on the 430 and 440, and is a $2600 option on the 420.

Larger 19-inch rims are fitted to the 430i and 440i cars, while the 420 gets 18s out of the box. It's possible to fit 18s on the more expensive cars, as part of the no-cost Luxury option pack that supplants the standard M Sport pack.

While our test was brief and held in less than ideal road conditions, the large-wheeled 4 Series really didn't enamour themselves to this author. There's a distinct lack of communication from the tyres and chassis through the steering wheel and your backside, while the combination of firm Sport shocks and large 19-inch wheels with narrow-section tyres made for an uncomfortable ride over country roads.

Sampling a 420i with the Luxury 18-inch rims, however, improved things immensely, with much better feedback and comfort that didn't come at the expense of handling.

One of BMW's strong points should be its steering, given all the 3 and 4 Series cars are still rear-wheel-drive… but it's not, unfortunately. The electrically assisted set up is far from perfectly calibrated, feeling too dull and digital underhand, no matter what the setting.

The pick of the bunch performance wise is – logically – the six-cylinder 440i. The turbo powerplant is potent from right down the rev range, with a muted yet still pleasing engine note permeating the cabin. The self-shifting mode on the eight-speed auto does a good job of keeping up as well.

The updated 2.0-litre four is a sprightly performer, too.

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'.

BMW offers a Service Inclusive program at the time of purchase, which for $1340 covers everything – including items like spark plugs, brake fluids and other fluids - for five years or 80,000 km scheduled. The cars are also covered by a three-year free roadside servicing program, in addition to BMW's two year, unlimited kilometre warranty.

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.