BMW M6 2013 review

Tuned BMWs have moved closer to their Mercedes and Audi rivals. If time is the ultimate luxury, then performance cars are a paradox. Flat out, even cars with modest performance ambitions can hit 100km/h in six or seven seconds. That used to be the supercar zone. Now, the quickest Italian exotics can hit the legal limit in less than half that.

When the Bugatti Veyron achieved a sub-three second sprint time almost a decade ago, it looked untouchable. Surprisingly quickly, its rivals have caught up.

The paradox arises because if you want to enjoy that engine and decide to give the throttle pedal your undivided attention, then in a matter of moments you'll have to ease off. All the fun comes in one quick blat. Premature acceleration, if you like. Keep going and you may end up serving time measured in months rather than seconds.

Of course, there's more to luxury and performance than outright pace. That's the province of muscle cars and Friday night drag racers.

VALUE

On price, the M6 Gran Coupe sits above the M6 coupe but below the convertible, at $299,500. Rivals include the Aston Martin Rapide, Maserati Quattroporte, Mercedes CLS 63 AMG, Porsche Panamera and upcoming Audi RS 7 and Jaguar XJR. Compared with other Gran Coupes, it's a $60k premium over the 650i with a lesser version of the same engine and $115k more than the 640i, which has a turbocharged inline six.

DESIGN

If a car can handle its socks off and rewards a driver, then pace per se becomes secondary. An example is the upcoming McLaren P1, spiritual heir to the maker's landmark F1 supercar from the 1990s. It does not claim to be the quickest in a straight line but the fastest around a track. Any track.

There's a trade-off here between the sorts of fittings you may expect in a car costing hundreds of thousands of dollars and handling. Luxury materials and gadgets add weight, the enemy of agility. The most extreme supercars are stripped of all that stuff to mimic, albeit in a more manicured way, the rawness of race cars.

Another type of performance car, though, where everything from the splendid cabin to the equipment to the engine are maxed out. These are epitomised by the tuned versions of mainstream cars produced by AMG for Mercedes, M for BMW and Quattro for Audi.

Here, the point is to give the ultimate luxury statement a fitting level of grunt, so that the big engine under the bonnet is an engineering match for the 20-speaker megawatt sound system.

These cars are increasingly popular, especially in Australia, which buys more of them per capita than just about anywhere else. Their success has spurred proliferation, with nothing too absurd to pimp. It's why the Mercedes G-wagen, a hardcore military offroader, is offered with a 400kW+ V8 in the G 63.

In that car, the engine is way out of kilter with the vehicle's dynamic ability. It's a case of having more because you can. To a lesser extent, though, that's true of all these cars. One example is BMW's 6 Series line-up, which has an M variant for each of the three body styles offered: coupe, cabriolet and sedan.

The M sedan, called the M6 Gran Coupe, has just arrived. It's one of those low-slung sedans makers like to refer to as a “four-door coupe”, hence the name. It's longer than the real coupe by more than 100mm and all of that is between the wheels to provide adequate seating in the rear. Unlike the coupe/convertible, it can carry five and offers decent legroom all round. In effect it's a 7 Series limo in a wetsuit, with all the bulges compressed out.

TECHNOLOGY

In other respects, it is virtually identical to the M6 coupe/convertible and the M5, with the same turbocharged 412kW 4.4-litre V8 and seven-speed, dual-clutch transmission driving the rear wheels. It weighs 25kg more than the coupe but can reach 100km/h in an identical 4.2 seconds.

Compared with the standard Gran Coupe, apart from the engine and transmission, the M treatment includes a high-performance chassis with unique axles, active dampers and an M differential to help put power down. It also gets a superb interior, with contrasting leather and Alcantara, a huge control screen and all the toys you can think of, including BMW's excellent head-up display.

SAFETY

The M6’s exceptional level of spec extends to front-side and curtain airbags, multi-stage stability and traction control, anti-lock brakes with six-piston front calipers, cruise control with braking function, active front head restraints, auto-dimming mirrors, several cameras, parking sensors, lane departure warning, tyre pressure monitoring, heads-up display and auto high-beam function. Carbon-ceramic brakes are also available for an extra $24,000.

DRIVE

The latest M5 and the M6 trio mark a change in direction for BMW M cars compared with the ones that came before. Typically, the M treatment produced a more focused result than its rivals at Mercedes and Audi. They traced their lineage back to race cars. An M3, for example, felt more at home on a track than the equivalent Mercedes C 63.

The price for that was commitment; driving on the daily commute did nothing to reveal its depth of ability and could be uninspiring. The C 63, by contrast, would snarl and rasp its way along at any speed. The latest M5/M6 change to fall into line with their rivals. The defining characteristic of these cars, unlike previous Ms, is an excess of power.

The M6 Gran Coupe is the same; it spins its wheels, finds grip momentarily, then spins them again in the next gear. On the road, particularly the damp and twisting back roads between Healesville and Phillip Island on the test drive route, that meant delicate throttle applications. Even then, the traction control light blinked non-stop.

The power itself is impressive. Once the engine reaches its torque peak, not far above idle, it just keeps going without respite. Some of it, thanks to the electronics, results in forward motion. It sounds snarly too, especially in low gears. However, it lacks the soaring character of the V10 unit in the previous M5/M6, which meant it had to be driven with the revs in mind. Here, power is on tap and delivers constant excess.

The result is a car that lacks a distinctive point of difference. The Gran Coupe, thanks to its length, is less agile than the coupe/convertible but I'm not sure I could tell the difference blindfolded, so to speak. The body feels rigid and the suspension firm, but on our country roads all that stiffness can unsettle the car and the ride is unbearable in anything except comfort mode.

On a track, by contrast, even in Sport+ mode you are aware of the weight transfer in directional changes and how much of the car's ability depends on super-wide rubber. When it comes to braking, even with huge stoppers you notice all two tonnes. After a couple of laps the brakes are smoking and starting to lose some of their force.

There are other downsides for the driver. The angle of the A-pillars means vision is restricted through corners and the rear window is a narrow slit, with fixed headrests no help.

VERDICT

The 640i was a car I enjoyed a lot when I drove it last year and I expected to like the M6 Gran Coupe more. But the 640i is a more balanced result.

No question, as a luxury statement the M6 Gran Coupe is right up there and the engine does its bit. But it shows BMW's M cars have joined the pack. Now I'm worried about what they'll do to the next M3.