M-Factor

No camouflage and no disguise – this is the F90 M5 unwrapped. Welcome to a new world of all-wheel drive performance

by MATT JOY pics WILSON HENNESSY

FIRST ENCOUNTER BMW M5

DESPITE having invented the modern sports sedan, BMW’s M Division found itself on uncertain ground with the 2011 F10 M5.

Early cars were marked down for numb steering and a lack of character from the first big M to embrace forced induction. Its main enemies – chiefly the W212 E63 AMG – nailed the brief from the outset and further dampened the F10’s thunder. Later tweaks and a Competition Pack brought back the sharpness, but the reverence with which the M5 had previously been regarded had been diminished. Something serious had to be done. The car you see here, the F90 M5, is it.

If you’re planning the world’s greatest sports sedan then raw materials come no finer than the current-generation 5 Series. The G30 generation is a huge step forward D over the F10, with its combination of aluminium, magnesium and highstrength steel. As the foundation for a composed and complete driving experience, it’s a better bet than what came before regardless of engine.

Perhaps more importantly, the G30’s CLAR platform-derived underpinnings are ready to accept xDrive from the start, allowing M Division to make the biggest call in its automotive history.

Panicking? There’s certainly room for dropped balls here. Two driven axles bring with them the scope for scorching standing starts and cast-iron composure in any weather. There’s also the implied threat of understeer, excess weight and numb steering, but let’s try to stay calm...

“Four-wheel drive was not a very difficult decision to make,” explains M Division boss Frank van Meel. “We built a prototype for evaluation, and for the first time we had an xDrive system that delivers the best of both worlds.

We have essentially added the option of front-drive on top of the rear-wheel drive system, with the software working out how and when the front wheels are driven. Right from the beginning the way the car drove was just special, so much more traction. The decision was very easy.”

“In the early days we kept our options open – we were still thinking of either rear-wheel drive or the xDrive system – but after we drove the M-developed xDrive system there was no further need for rear-wheel drive.”

For the new M5, the xDrive system is paired with an Active M differential, with bespoke software controlling the integration of the two. Better still, thanks to the front/rear torque split options available, the now familiar M Dynamic Mode has a much bigger influence on the car’s behaviour than has been the case in any previous M machine.

We know this because we’ve driven the prototype. On start-up the car defaults to its most benign settings, with stability control on high alert, torque directed primarily to the rear wheels and

“We off er this spectacular mode for those who want it, for those who want to drift or do doughnuts”

What makes the F90 special?

Dissecting the new M5

WEIGHT

EVEN with the new M xDrive system underneath, the F90 weighs less than (at 1855kg) its forebear thanks to a carbon fibre-reinforced plastic roof and a lighter exhaust system.

Optional carbonceramic brakes cut 23kg from the total.

GEARBOX

FOR the first time the M5 uses a Steptronic auto (not a DCT) for smoother shifts at regular speeds, while still delivering rapid-fire shifts. Familiar throttle, damper and steering options can be assigned to the racy red M1 and M2 buttons found on the steering wheel.

XDRIVE

ALL-WHEEL drive is masterminded by the Central Intelligence Module. Its tools are the transfer ’box and the Active M Diff, which sits in a meaty subframe at the rear. System analysis streams the data before working out the best place to put the V8’s force.

BODY

THE G30’s bodyshell is a fine start point, but the M5’s rear axle has been pinned down with heavy additional bracing. Up front, a new bulkhead reduces flex at the front struts. Both claim to provide a more rigid platform from which the M-fettled suspension can work.

shifting power forwards when slip is detected.

“With the combination of power and rear-wheel drive we were getting very narrow in the M5’s versatility,” explains van Meel. “You had to be an absolute expert, and if the weather conditions weren’t ideal you would see your DSC light flickering all the time and you wouldn’t get the performance you wanted out of the car. So in order to give more out of the car. So in order to give more performance in all conditions, we went all-wheel drive. That was one of the key reasons. Now everyone that drives the car is impressed.”

Ratchet things up via the M Dynamic Mode selector and you get big changes; the 4WD Sport setting means reduced output to the front wheels while DSC intervention is wound down a fraction, giving you the option of degrees of oversteer. Turn DSC off and you can have a few more degrees, with a little power still sent to the front axle to keep you pointing in the direction of travel.

And finally there’s a mode for the old school, those who say no true M car would have four-wheel drive, and who reckon they’ll switch it into twowheel drive before they even get off the twowheel drive before they even get off the driveway, merrily ignoring BMW’s recommendation that the mode is for track-use only.

But they might change their minds quite quickly given the hopelessness of two (optional) 285/30 20s being asked to cope with 750Nm of torque in a country where road maintenance is the punchline to a long-running joke. Nevertheless, van Meel insists the hero mode had to be there.

“We started with a rear-wheel drive car and added the traction system on top for the situations where you need it. The psychology of the game was that we had to get [beyond the idea]that fourwheel drive is poor. An xDrive is rear-wheel drive with more traction. We offer this spectacular mode for those who want it, for those who want to drift or do doughnuts. If you want to use the 2WD mode you have to switch the DSC off, because if you leave it on you would have continuous DSC intervention. This way you can do powerslides or whatever. You can have DSC switched off altogether, but switch between 4WD, 4WD Sport and 2WD too.”

There are no such seismic shifts of direction in the engine room. This is broadly the same twin-turbocharged V8 from the F10, but the S63B44T4 unit has been worked over to put clear water between the new M5 and the previous-generation car.

The twin blowers are to a new specification to deliver better response, while the manifolds that feed them have been redesigned for better flow. Injection pressures have been ramped up to 350 bar to allow shorter injection times, boosting output, efficiency and response.

Fast-road or track-readiness is evident in the beefed-up oil and cooling systems, which are more efficient and lighter than before. Nail Southern Loop at Phillip Island just as hard as you like and high lateral-g oil starvation won’t be an issue. Its 441kW is the same peak output as the F10 30 Jahre, but 750Nm of torque makes this the gruntiest M5 yet. A new exhaust system with an electronic flap brings the noise, cranking up the volume in line with the selected drive mode – though you can silence it at the push of a button.

Having dabbled with an SMG transmission in the E60 and then a DCT ’box in the F10, M Division has fallen in line with the current trend for autos by fitting the F90 with an M-modified Steptronic unit. Drivelogic control means any concerns about slushiness

A new exhaust system with an electronic fl ap brings the noise, cranking up the volume in line with the selected drive mode

INTERIOR

EXPECT to spend a lot of time looking at the screen. In the M5 the iDrive or touchcontrolled system keeps you up to speed on your chosen xDrive setting and how much DSC you’ve got wound on. Info is doubled up on the driver’s display, too.

NUMBERS

ON-PAPER figures are hard to ignore with the F90. The 4.4-litre V8 punches out 441kW/750Nm, it can reach 100km/h from rest in 3.4sec, hit 200km/h in 11.1sec and top out at 305km/h with the M Driver’s Package optioned.

can be dismissed: The default mode brings smoothness and economy; mode two ups the shift speed; and mode three delivers the fastest shifts, including multiple downshifts from a single pull of the paddle.

Such go-faster M fairydust is evident elsewhere, too. The double-wishbone front and five-link rear suspension layout is as per the standard car, but there are stiffer anti-roll bars and bushes, the rear axle gets additional steel and aluminium crossbraces and at the front there’s a new aluminium bulkhead to stiffen up the nose and the front struts, all the better to provide the sharpest steering response. The six-piston front calipers use a specially designed pad compound to shave weight without losing power, while the optional M carbon ceramics are even lighter.

The visuals lay the essential elements of an M car – the quad pipes, discreet M-colour flicks and subtle menace – over the restrained good taste of the G30 5 Series beneath. The front bumper receives the full ground-sniffing treatment, with big vents to feed the engine and cool the brakes. And while the M5 retains the standard car’s aluminium body, there’s a carbon roof as standard. At the rear, the exhausts punch neatly through the revised rear bumper/diffuser, and there’s subtle additional aero; a rear lip spoiler, sharp side skirts.

All-wheel drive promises to make this the most versatile M5 yet, and the interior follows suit, with comfort and refinement rather than any kind of track-bred minimalism. Up front there are M-specific seats with meatier base and back bolsters. Adjustment options are myriad, and stretch to electric adjustment of the width of the backrest for a just-so high-speed embrace. The illuminated M badges we can probably live without, though.

The cabin retains its spacious, comfortable approach but with Tabasco dashes of M; in particular the M1 and M2 shortcuts on top of the steering wheel spokes are picked out in flare red, as is the starter button, just in case you’re not already in the mood.

From our time in the prototype, we’ve no doubt the M5’s xDrive system is progress, and most welcome. Standard xDrive is compelling enough, and M’s take on all-wheel drive simply offers more of everything: More all-weather grip and talent when you’re pushing in wet conditions, and more controllable fun when you’re ESC-off and living on your wits.

Really, the only concern with the M5 is the quality of the BMW’s old adversary, the Mercedes E63 S. That car, too, has embraced a driven front axle, of course. In S guise its extrovert twin-turbo V8 is the stronger engine; 450kW and 850Nm plays the BMW’s 441kW and 750Nm. The M5 must hit back with a stellar chassis and elegant integration of that all-wheel drive drivetrain (tune in the next issue or two for our first international drive of the finished product). If it does, then far from ruining M Division’s very fast Five, a driven front axle will have saved it. M

The visuals lay the essential elements of an M car – the quad pipes, discreet M-colour fl icks and subtle menace

It Runs In The Family

Legendary M5s

1998

FOUR DOORS, rear-wheel drive and a snarling naturally aspirated V8 up front – it’s a recipe for greatness. The E39, at the time, was a massive departure from M5 tradition, swapping out the atmo straight six of the E34 for a bored-out version of the S62 with VANOS, meaning the 4.9-litre (marketed as a 5.0-litre) bent eight returned 294kW/500Nm. The manualonly E39 hit 100km/h in 5.2sec and covered 400m in 13.5sec.

2005

THE E60 M5 not only heralded yet another cylinder-count change, upping the ante to a V10, it ushered in a new age of electronic trickery. You could calibrate the engine (298kW and 378kW modes), seven-speed gearbox, steering, traction control and damper control. Or, you could just hit the M button, which facilitated a 0-100km/h time of 4.7sec.

A cool Touring (E61) version was available in other markets, while the US got a manual.

The Specs Bavarian super sedan BMW M5

BODY 4-door, 5-seat sedan DRIVE all-wheel ENGINE 4395cc V8, DOHC, 32v, twin-turbo BORE/STROKE 89.0 x 88.3mm COMPRESSION 10.0:1 POWER 441kW @ 5600-6700rpm TORQUE 750Nm @ 1800-5600rpm POWER/WEIGHT 238kW/tonne TRANSMISSION 8-speed automatic WEIGHT 1855kg SUSPENSION (F) double A-arms, adaptive dampers, antiroll bar SUSPENSION (R) multi-links, adaptive dampers, anti-roll bar L/W/H 4665/1903/1473mm WHEELBASE 2982mm TRACKS 1626/1595mm (f/r) STEERING electrically assisted rack-and-pinion BRAKES (F) 395mm ventilated discs, 6-piston fixed calipers BRAKES (R) 380mm ventilated discs, single-piston floating calipers WHEELS 19.0 x 9.5-inch (f); 19.0 x 10.5-inch (r) TYRE SIZES 275/40 ZR19 (f); 285/40 ZR19 (r) TYRE Michelin Pilot Sport 4S PRICE $230,000 (estimated)