BMW's new M4 coupe reviewed
This is the new M4 coupé, successor to the iconic M3 coupé and sister car to the four-door M3. Not only does the M4 create a whole new model designation for itself, it also houses a number of new driveline developments, including a new turbocharged in-line six-cylinder engine.autos Updated: May 29, 2014 16:34 IST
This is the new M4 coupé, successor to the iconic M3 coupé and sister car to the four-door M3. Not only does the M4 create a whole new model designation for itself, it also houses a number of new driveline developments, including a new turbocharged in-line six-cylinder engine.
This new powerhouse produces a power peak of 422bhp and 56kgm of torque. The carmaker has managed to slash the weight of the car by 83kg with the use of lightweight materials, although the optional seven-speed dual-clutch automatic M-DCT gearbox, adds 40kg over the six-speed manual, taking the M4 coupé to 1,537kg.
When it comes to driving dynamics, the coupé offers marvellous ease of driveability and extraordinary refinement at one end of the spectrum, along with amazing pace and tremendous dynamic proficiency at the other. It may be clichéd, but it really is a car for all occasions.
The key to its broad spread of talent is its Drive Performance Control, which allows the driver to tailor the properties of this new M-car over a significantly wider range than its predecessor. Accessed via three buttons on the centre console, you get the choice of Efficiency, Sport and Sport+ modes for the engine mapping together with Comfort, Sport and Sport+ modes for the suspension damping and electro-mechanical steering.
And unlike on standard models from the carmaker, which restrict you to one common mode for all, this car allows you mix and match the engine, damping and steering setting to suit your needs. An M-mode function also allows you to save preferred combinations, which can then be easily accessed via a pair of buttons on the steering wheel.
In comfort mode, the car is not even remotely demanding. You could cover kilometres and kilometres without ever feeling remotely challenged – all in a sumptuous environment offering outstanding levels of interior comfort and first-rate ergonomics. In this sense, this coupé proves to be a convincing everyday proposition.
But if you ever feel the need for the car to be more engaging, simply nudge the buttons down beside your thigh to engage Sport and it instantly becomes more purposeful in nature. The properties of the driveline, chassis and electronic driving aids are altered to give a more urgent action to the steering and added aggressiveness within the throttle mapping, while satisfying damping compliance gives way to a slightly stiffer ride and the calibration of the electronic stability control suddenly becomes a lot more liberal, allowing you to entertain the hooligan within when conditions permit.
Moving up into Sport+ further heightens the experience, although it is really only intended for track work and proves wearing for any distance on public roads.
The driving position is excellent, supported by newly designed sport seats offering a wide squab, plenty of lateral support and a good deal more adjustment than you will likely ever need. The clarity of the unique instruments, superb weighting of the controls and the quality of the materials leave you in little doubt that you’re aboard something special.
Like all M-cars down through the years, it is the engine that moulds the driving experience more than anything else. And it is here where the new twin-turbocharged six-cylinder unit both impresses and disappoints. At start up, it sounds remarkably similar to the twin-turbocharged V8 from the M5, with an odd diesel-like chatter to the engine and a raspy exhaust note. Thankfully, it improves as you select first and move off.
Predictably, the single biggest change over the M3 coupé is in the delivery, which couldn’t be any more different than before. With all that torque concentrated low down, there is substantial shove from little more than idle. This results in outstanding flexibility across a much wider range of revs, making it much better suited to stop/go city driving than its predecessor.
Just don’t count on the same razor-sharp throttle response as before when the road opens up and you get to put your foot down. The inherent qualities of the forced-induction engine mean the initial pick-up is a lot less rabid than with the old naturally aspirated unit owing to a fleeting moment of lag as the two turbochargers spool up to full boost. But once they do, the in-gear shove is uncompromising.
Still, there's no need to pile on the revs in an attempt to tap into the deep seam of performance offered by the new engine. You merely flex your right foot in a suitable gear and the engine obliges with truly muscular properties. The resulting rush of acceleration is spectacular, particularly between 3,500 and 5,500rpm where it feels to be at its strongest.
Inevitably, though, it lacks the outright aural intensity of the unit it replaces, despite the inclusion of Active Sound Design, which reproduces the sound of the new six-cylinder through the audio speakers at various volumes and frequencies based on engine revs, throttle load and speed.
With two mono-scroll turbochargers, variable valve timing and continuously variable camshaft control, it revs quite freely, extending to 7,600rpm before the onset of the limiter. This is quite high by turbocharged engine standards, but 600rpm less than the old naturally aspirated engine achieved.
The optional dual-clutch automatic gearbox provides the new car with the ease of usability to match its fervent on-boost accelerative ability, leading to a highly impressive set of performance figures: 0-100kph in 4.1sec and the standing kilometre, now very much accepted as the modern day acceleration yardstick, in 22.2sec. This is a respective 0.5sec and 0.7sec faster than the old M3 coupé.
As a further indicator of just how much the new engine has transformed the performance, BMW claims the new car is capable of accelerating from 80 kph to 120kph in fourth gear in just 3.5sec. By comparison, the earlier coupé required 4.3sec. Top speed remains limited to 250kph, although buyers can have it raised to 280kph with an optional M Driver’s package.
It is not just the sheer potency of its straight-line acceleration and heaving in-gear qualities that makes the new coupé so exciting to drive hard, though. There is a perceptible completeness to the engineering of its chassis that serves to provide the new M-car with a wonderfully fluid feel over challenging sections of blacktop.
Directional stability is exceptional, even at very high speeds. The electro-mechanical steering system also delivers excellent response, impressive directness and more constant weighting through its entire range than the old hydraulic arrangement it replaces. It could do with a little more feedback, but with Sport or Sport+ modes engaged, it delivers suitably urgent turn-in traits.
The front end offers exceptional grip without any premature breakaway provided the surface is relatively smooth. With stability clutch control, which opens the clutches when sensors detect the loss of imminent traction and briefly reduces power to bring the car back on line, it resists understeer in a masterful manner, resulting in wonderfully neutral properties even in tight second-gear corners.
Body control is also superb, providing the new M-car with a reassuringly flat cornering nature even when you begin to nibble at the very last remnants of available purchase. There is a wonderfully composed feel to the handling all the way up to the point where the dynamic stability control (DSC) intervenes.
This is partly down to it boasting a lower centre of gravity than the car it replaces, but, I suspect, more because of the work that has gone into providing its largely bespoke suspension with ultra-stiff anchoring points.
BMW M division’s decision to provide it with a new steel rear suspension sub-frame that bolts directly to the body structure without any rubber bushings gives the new car tremendous on-the-limit clarity. The lines of communication are amplified to a whole new level, revealing its willingness to oblige beyond the dynamic boundaries of the earlier coupé.
The adoption of a carbon fibre-reinforced plastic driveshaft has also added greater overall progressiveness to the handling thanks to lower reciprocating masses and the scope for a whole new approach to the settings of the electronically control active differential, allowing you to send it sideways at will with the DSC disabled.
BMW M chiefs say the M4 coupé is 15sec faster than the old M3 coupé around the Nürburgring, where much of its chassis development was carried out. Part of the gain is down to the added performance delivered by the new turbocharged engine. However, it is clear the handling has also risen to a lofty new level as well.
An even bigger achievement in my eyes is the new car’s broad spread of ability. You can cruise along the motorway in admirable comfort with the steering in a relatively relaxed state, the suspension offering excellent compliance, the engine in its most efficient state and the DSC at the ready.
Then you can head out on to the track with the steering feel heightened, the chassis primed for ultimate body control, the throttle mapping set for maximum attack and the electronic safety net disengaged in a bid to better your lap time.
However, there are apparent shortfalls. While it is spectacularly powerful and endows the M4 coupé to previously unattained levels of acceleration, the new engine lacks engagement and sounds disappointingly flat at certain points in the rev range. It also fails to match the sheer response of the engine it succeeds.
For many potential buyers who might consider the BMW M4 coupé, this will blunt its charm, but only until they discover the gains in driveability and stunning in-gear qualities. What it lacks in overall excitement, it more than makes up for in everyday driving appeal.