BMW M4

The 'M' Stands For Monstrous

13th February 2015

Michael Woodhouse reviews the BMW M4

Price: from £56,635 • Model tested: turbocharged 3-litre in-line six-cylinder

Top speed: 155mph • 0-62mph: 4.3 seconds • Power: 431hp • Fuel economy: 32.1mpg • CO2 emissions: 204g/km

Mindless, exasperating, mindblowing, a blow to the solar plexus. All ways to describe power. That’s what you get when you put your name down for one of BMW’s M-division models. And it doesn’t matter if its badge is placed on a big SUV or a smaller vehicle, the ‘M’ stands for monstrous.

Integrating a turbocharged 3-litre in-line six-cylinder petrol engine (431hp of power and 550Nm of torque) in a convertible that weighs 1,497kg means hitting 62mph in 4.3 seconds. In fact, if you choose the dual-clutch transmission over the manual, that drops down to 4.1 seconds. It’s an explosive amount of performance from a car that doesn’t necessarily look as if it could keep up with vehicles that cost double, if not triple, the price.

But engineers have spent a lot of time making sure that not only can the M4 convertible mingle with every day runarounds, but it can also keep up with the Joneses.

Viewed from the front, BMW says that the M4 have a ‘powerful face’ – which I’m not sure I agree with – and ‘a modern take on the twin headlight arrangement and a distinctive double-slat kidney grille’ – which I’m not sure I understand. But the front apron, and trio of large intakes that supply cooling air to the engine and brakes do make it look aggressive. The dark colour of the carbon fibre reinforced plastic roof, which helps keep weight down, gives the convertible a low-slung, sporty appearance.

At the rear the convertible features an integrated spoiler made from a carbon-fibre compound and flared rear wheel arches, which, in combination with the wide track, hint at the power that lays beneath and twin exhaust tailpipes.

In a brash colour the M4 might shout a bit more about its performance, but in the black version I drove, even the flared arches didn’t make it look as overtly aggressive as performance vehicles from Audi and Mercedes-Benz.

Inside the cabin it’s very much BMW fare – but an M-Division car is all about the engine, and this engine is something special.

It sees a slight power upgrade over the previous V8 unit used to 431hp – not bad when you’ve lost two cylinders – and it arrives between 5,500 and 7,300rpm. Peak torque is also up by roughly 40% cent to 550Nm, and is available between 1,850 and 5,500rpm.

Without wanting to get too heavy, one of the reasons for the improvements is that the six-cylinder engine features a closed-deck crankcase design, which is very rigid and allows cylinder pressures to be increased for improved power output. And instead of liners, the cylinder bores feature a twin-wire arc-sprayed coating, which results in a significant reduction in engine weight. You don’t really need to know this – but what you need to know is that as with any M car, the M4 convertible provides not only an aural pleasure as you whip through the gears, but the simple delight of a large displacement engine in a lightweight car.

I was behind the wheel of the dual-clutch transmission, a fairly smooth gearbox that blips the throttle automatically when you downshift, should you choose to take charge to make you feel like a slightly better driver than you actually are. But I’ll be honest, if you’re spending more for any type of automatic gearbox, you’re buying it so you don’t have to change gear. And left to its own devices, it’s a wonder that you’ll only notice how good it is when you arrogantly take over.

For most people, trying to achieve the standard sprint from 0-62mph in 4.3 seconds in the manual might be a challenge. The quicker time of 4.1 seconds, in the dual-clutch might be that little bit more achievable. What’s gratifying is that the performance is available and without a huge penalty in efficiency. The M4 emits as little as 194g/km and manages 34mpg on the official test cycle. Yes, I know official mpg figures are often somewhat of a joke, but you need some sort of comparison. And the M4 does better than my seven-year-old old Mazda 6 – with a lot more potency.

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