Infiniti Q50 vs BMW M4

What's the difference?

The Q50 Red Sport is a premium sedan that's great value, with a cracker of an engine. While Infiniti has improved the ride and steering, it still feels to me that the engine is too powerful for the wheels and chassis to handle. But if you're looking for something of an untamed beast, this car could be for you. Just don't say we didn't warn you.

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 Q50 Red Sport looks cranky from front on, which I like in a car. Yes, the grille is simplistic and gaping, the nose is a bit bulbous, and sure, side on the car looks like a Lexus IS 350, but those rear haunches and the aggro body kit with its front splitter and boot lid spoiler make for an impressive looking four-door sedan.

The update brought restyled front and rear bumpers, those red brake calipers and the dark chrome 20-inch rims and new LED tail-lights.

Inside, the cabin is an asymmetrical paradise (or hell, if you're a bit OCD like me) full of sweeping lines, angles, as well as different textures and materials.

The red stitched quilted leather seats are an addition that came with the update, so is the new steering wheel and the ambient lighting.

The 'Sunstone Red' colour of our test car is also a new hue which looks a bit like Mazda's Soul Red. If red is not you, there are other colours – hope you like blue or white or black or grey because there's 'Iridium Blue', 'Midnight Black', 'Liquid Platinum', 'Graphite Shadow', 'Black Obsidian', 'Majestic White' and 'Pure White'.

The Q50 has similar dimensions to the IS 350: both are 1430mm tall, the Infiniti is 10mm wider at 1820mm,  120mm longer at 4800mm, and has a wheelbase that's 50mm longer at 2850mm.

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 Q50 Red Sport is a five-seat four-door sedan and is vastly more practical than its two-door Q60 Red Sport sister, in that I can actually sit in the back seat. The Q60's coupe styling looks amazing, but the sloping roofline means headroom is so severely limited that it reduces the rear seats to a place to throw your jacket.

True, I'm tall at 191cm, but in the Q50 Red Sport I can sit behind my driving position with legroom to spare and more than enough headroom.

Boot space is good at 500 litres, which is 20 litres more than the luggage capacity of the IS 350.

Storage throughout the cabin is good with two cup holders in the rear centre fold-down armrest, two more up front and bottle holders in all doors. A large centre console storage bin and another big storage area in front of the shifter are great for keeping junk under control and your valuables covered.

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.

Inside the Q50 Red Sport's nose is a 3.0-litre twin-turbo V6 petrol engine and it is a beautiful thing. To me this car is piece of technologically sophisticated jewellery that cradles a precious gem that pumps out 298kW/475Nm.

But I have my concerns... you can read about those in the driving section.

Shifting gears is a seven-speed automatic which delivers drive to the rear wheels.

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'.

Infiniti says the V6 petrol engine in the Q50 Red Sport should use 9.3L/100km if you're using it on a mix of highways, urban streets and country roads. We only had the Q60 Red Sport for 48 hours and after a couple of days of Sydney city commutes and a trip to the Royal National Park our trip computer was reporting 11.1L/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.

Perhaps the biggest complaint we had about the previous Q50 Red Sport, which launched in 2016, was that it felt as though the chassis wasn't up to the amount of grunt running through it, and those rear wheels struggled to transfer the oomph to the road without losing traction.

We experienced the same issue again in this new car. I was breaking traction, not just in 'Sport+' and 'Sport' modes, but in 'Standard' and 'Eco', too. That was happening without pushing it hard and with all electronic traction and stability aids on.

If I was 18 I'd declare to the world I'd found my dream car - something that always wants to 'light 'em up' given half a chance. But like that one mate who always gets into trouble on a night out it's only funny when you're young.

A truly great performance car is planted, balanced and able to deliver the grunt to the road effectively. The Nissan R35 GT-R is the perfect example – a brilliant piece of machinery, a weapon of a performance car and with a chassis matched perfectly to its engine.

And that could be the issue with Q50 Red Sport - that engine feels overpowered for the chassis, and wheel and tyre package.

We also felt the previous Q50 Red Sport's ride, with its constantly adapting 'Dynamic Digital Suspension', was overly busy. Infiniti says it has developed the suspension system further and it does feel as though the ride is more comfortable and composed.

Steering was another area that we weren't overly impressed with when we drove the previous car. Infiniti's 'Direct Adaptive Steering' (DAS) system is super sophisticated and was the first in the world not to have any mechanical connection between the steering wheel and the wheels – it's all electronic.

The new Q50 Red Sport uses the upgraded 'DAS 2' and while it feels better than before, it's only in Sport+ mode that it seems most natural and accurate.

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 Q50 Red Sport is covered by Infiniti's four year/unlimited kilometre warranty with servicing recommended every 12 months or 15,000km.

Infiniti has a scheduled servicing program which will cost $1283 (in total) for three years.

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.