BMW M4 v Mercedes C 63 AMG Coupe 2014 Comparison

The pressure to produce a worthy successor to the legendary E90 (four-door) and E92 (two-door) M3, while improving technology, performance and efficiency has been the M-Division engineers’ greatest challenge.

For the first time the two- and four-door M variants have been separated by name, the coupe now called M4 to follow BMW’s now-familiar numbering convention (odd numbers for sedans, evens for coupes). Under the skin, however, they effectively remain twins.

By introducing turbocharging on an ‘M3’ for the first time, BMW has taken a brave step, but it now has a precedent with the M5/M6. The reality is simple: turbocharging allows a capacity (and cylinder count, in this case) reduction to improve fuel consumption. Turbo motors are also inherently more efficient, pumping more air into the motor to aid the combustion process.

The 3.0-litre twin-turbocharged petrol unit sees a return to an inline six for the 3 Series-based M cars, usurping the 4.0-litre naturally-aspirated 8400rpm V8 in the previous model.

Rated at 317kW, the new machine produces slightly more power than its predecessor’s 309kW, but gains massively in torque, the M4’s 550Nm thumping the 400Nm E92. Efficiency improves from 11.9 to 8.3L/100km on the combined cycle.

There remains a choice of (special-order) six-speed manual or seven-speed dual-clutch transmissions, and the Active M Differential offers a lockup range of 0 to 100 per cent. Cockpit-selectable Comfort, Sport and Sport + modes adjust throttle response, steering and damping accordingly.

At 1560kg, the M4 DCT has also been on a diet, shaving around 65kg from a similarly-specified E92, despite being a physically larger vehicle.

Priced from $166,430, the tested vehicle contains the following cost options: Black 19-inch M light alloy wheels ($500); Roller sunblind for rear window ($800); Driving Assistant ($900); Adaptive LEDs with high-beam assist ($2360); Head-up display ($1700); Merino full leather upholstery ($2700); Internet ($200) and Connected Drive Freedom package ($1200), for an as-tested price of $176,790.

Fitting finale
The C 63 507 Coupe is the last of a dying AMG breed. We now know it will be replaced by a turbocharged downsized 4.0-litre V8, so please indulge us while we celebrate the 6.2-litre naturally-aspirated V8’s finale.

In Edition 507 form, the 6208cc (ignore the 6.3 nomenclature; it’s a marketing link to the 300SEL 6.3 of the past) M156 pumps 373kW and 610Nm, putting it in another on-paper league to the M4, and the fact that such large engine revs – comfortably and snortingly – to 7250rpm still boggles the mind.

But if its outputs are inter-dimensional, so are its fuel figures. At 12.1L/100km, the C 63 both goes and drinks like a rocket.

That grunt goes to the rear tyres via the familiar seven-speed ‘Speedshift’ automatic transmission and a good old-fashioned mechanical limited-slip differential.

Priced below M4 at $159,507 (plus on-road costs), the C63 Edition 507 coupe comes in at $161,497 as-tested, the only option being the matt black 19-inch alloys at $1990. 

Initially, the M4 disappoints, and it’s down to the engine. Thumbing the starter button of an M-car should be an event, but the M4 sounds tinny, deliberately loud, and contrived.

The acoustics improve with revs, but you never escape the feeling that it’s artificial, trying to overcome the inherent whoosh of the twin turbos.

Although responsive enough for most of its 7600rpm rev-range, the M4 has replaced the previous M3’s thrusting top-end with a wide-ranging torque spread, peak torque available from only 1850rpm.

But where you could dance the E92 on the edge of traction, when the M4 breaches rear grip you have to be super-fast and accurate in your steering and throttle inputs to avoid spinning.

“It wants to drive straight, rather than sideways,” is Editor-in-Chief Mike Sinclair’s summation.

It’s at the front-end, however, where the M4 impresses. Through responsive steering the BMW bites for corners with poise and incisiveness, though it’s best to give the Sport Plus steering settings a miss; Sport gives a fine balance of weighting and accuracy, if not feel.

If you drive the M4 clean and straight, making use of its prodigious braking ability (carbon-ceramics are a $12,000 option, but the standard four-pot/two-pot front/rear system works nicely) and metering out throttle on exit, it becomes a scalpel.

“If the M4’s a precision instrument, the C 63 is a bludgeoning weapon!” says Mike after a lap in the Affalterbach future classic.

From its thumping V8 to its penchant for being steered on the throttle, the Merc is the more boisterous of the two on-track.

The edges of its performance are smoother than in the BMW, and you can feel the limits of grip bleeding away rather than snapping suddenly.

Having said that, the steering response is slower, the gearbox now feels its age against the M4’s refined DCT and the ultimate grip levels just aren’t there, the front-end mass leaning the AMG towards understeer.

Of course, countering that with a boot full of throttle is always fun, but while that looks good for the cameras, it’s ultimately slower.

Braking-wise the 507’s larger 361mm two-piece front rotors and six-pot front/four-pot callipers offer consistent pedal feel and solid braking, especially considering its 1766kg kerb weight.

But it’s that characterful motor that steals the show. Elastic throughout the range, the C 63 507 retains a top-end savagery that makes a mockery of its mass, and it’s coupled with a traditionally thunderous V8 bellow.

In almost every conceivable way the M4 is the better touring car, with its multiple damper settings capable of providing ride comfort or tautness at the flick of a switch, less intrusive road noise, more intuitive cabin controls and more efficient engine. In-car technology, with ConnectedDrive and head-up display in the test car, is exceptional.

Both vehicles feature a multitude of adjustment to seating and steering wheel position, making long-haul drives a relatively pain-free process, and both audio systems are more than capable.

The single-setting dampers of the C 63 offer a good ride/handling compromise for a sports car, but it never feels less than taut. Even though the V8 is reduced to a whisper at freeway speeds, it allows far more road and wind noise into the cockpit than the M4.

Couple that with the busier centre-stack, sloppy slow-speed transmission response and less user-friendly tech functions (such as sat-nav) and the C 63 is a more intense on-road experience.

On a mix of freeway and flowing country road driving fuel consumption for the M4 was constant at 9.0L/100km, the C 63 at 12.7L/100km; both above their claimed combined averages.

The enthusiast in me is saddened by its dilution of character (mostly through the contrived engine note and steering) and its edgy, unfriendly dynamics, but on-road (where, let’s be honest, these cars are designed to be) the BMW is simply the better machine.

Will it be enough to beat the next-gen C 63, a car based on the brilliant new C-Class? We can’t wait to find out.