BMW M5 2011 Review

OVERVIEW?

It's not all about styling, of course. There's a new, twin-turbo petrol V8 engine that offers peak power and torque of 412kW and 680Nm — more than enough for most owners. And in contrast with the V10 that powered the E60 model of M5, the new engine delivers more accessible power and performance. There's enough torque for the M5 to missile off down the track in practically any gear.

For the icing on the cake, BMW claims to have reduced fuel consumption and CO2 emissions in combined cycle testing by a considerable margin — now 30 per cent lower than the E60's figures. We've actually done the sums ourselves, and estimate that the improvement is more like 35 per cent, based on the new car's 9.9L/100km and 232g/km stats.

Along with the improvements brought to the entire 5 Series range with the introduction of the F10 generation models, the M5 also gains weapons-grade drivetrain components, including a seven-speed dual-clutch transmission and the Active M Differential at the rear.

It won't, however, feature the Speed Limit Info facility integrated in the Head-Up Display, due to the complexity of local speed limit zone signage. And the iPhone apps, which are a major feature of the new M5's equipment list won't pass muster under Australian Design Rules, so cross those off as well.

The features that will be practically a given for locally-delivered cars will include: four-zone climate control, electrically-adjustable heated front seats with memory, adaptive xenon headlights with High Beam Assistant, alarm, satellite navigation with hard disk drive, electrically-operated glass sunroof, Park Distance Control, reversing camera, Lane Departure Warning, Surround View and Night Vision with pedestrian detection.

MECHANICAL
-- Performance on demand, but kinder to the environment
What sets the new M5 apart from the model it replaces is the twin-turbo V8, which offers plenty of mid-range torque and linear power delivery right through to the redline. There's none of the peakiness reported by drivers of the V10-engined E60 M5. Catering to that need for torque lower in the rev range the 4.4-litre V8 is an undersquare design — with a bore of 88.3mm, versus a slightly longer stroke of 89.0mm.

Power-to-weight is now 3.3kg/hp — a significant improvement on the older car's figure, according to BMW. An acceleration time of 4.4 seconds to 100km/h for the new M5 is the direct result of outright power (412kW) and muscular torque (680Nm). But output is just one side of the new engine's character; BMW also claims to have shaved 30 per cent off the combined-cycle fuel consumption and CO2 emissions for the new car, measured against the V10 model. Those new figures (9.9L/100km and 232g/km) are a consequence of incorporating a cross-bank exhaust manifold for the turbochargers, direct petrol injection and Valvetronic variable valve control. Otherwise, the V8 shares much of its architecture with other V8-engined models in the BMW range.

The M5 remains rear-wheel drive, with a seven-speed dual-clutch transmission conducting the engine's torque to the rear wheels via BMW's Active M Differential — a multi-plate limited-slip diff regulated and monitored through an electronic link to the stability control system. BMW asserts that the intelligent diff can split torque 0:100 – that is 0 per cent on one side and 100 per cent on the other. This will, the engineers advise, depend on external factors including throttle position, wheel rotation and vehicle yaw rate.

The way the M5 operates, dynamically, can be controlled and adjusted from the driver's seat via three mode buttons on the centre console. These allow the driver to scroll through Comfort, Sport, Sport+ modes for ride quality and steering assistance (and the same three modes plus Manual mode for the drivetrain's response). Traction control can be disabled for fun on the racetrack (press M Drive button for 'MDM' — M Dynamic Mode) and the stability control can, additionally, be disabled in part ('DSC Off'). On the left spoke of the steering wheel are two 'M Drive' buttons which can be customised for different drive setting options, much like the favourites buttons that can be programmed for different iDrive settings.

BMW has stayed with hydraulic assistance for the M5's rack-and-pinion steering, which is controlled by the company's Servotronic computerised system. Compound-construction brakes feature six-piston fixed calipers at the front and single-piston fixed calipers at the rear. Ventilated all round, the disc rotors measure 400x36mm at the front, 396x24mm at the rear.  

The rotors sit within 19-inch alloy wheels in a paired-spoke design and the Michelin Pilot Super Sport tyres fitted at the factory measure 265/40 R19 at the front, 295/35 R19 at the rear. According to German automotive testing authority, TUV SUD Automotive, the Michelins posted the fastest lap times on a dry-circuit test against five competitors.

The M5 comes in under five metres in length (4910mm), sitting on a 2964mm wheelbase that contributes to the car's turning circle of 12.6 metres. Width measures 1891mm and height is 1456mm. Luggage capacity is 520 litres and the car weighs 1870kg unladen.

PACKAGING

Once the bolstered driver's seat was set up to suit the reviewer there was a little bit of contortion required to slip into the seat through the open door. It doesn't seem to be an especially wide opening, but that was with the wheel reach adjustment set closer to the driver than many will prefer.

The Head-up Display was a useful facility that outshone the satnav's voice commands for clarity. It also conveyed the prevailing speed limit for the driver to note, a worthwhile feature that we may not see in Australia for some time.

The shift paddles are solid-feeling fixtures that rotate with the wheel — and were a boon on more than one occasion at the Ascari racing circuit (see ON THE ROAD below). That steering wheel is the just right size for press-on motoring, both in diameter and the thickness of the rim.

Seats are comfortable and supportive too. At no point during the on-track session did the reviewer slide around or submarine at all. And conversely, the cushioning is noticeably softer than that of the Benz SLS AMG Roadster driven recently. Adjustable lumbar support for the front seats of the M5 should make all the difference in terms of comfort on longer trips.

Rear-seat accommodation is generally good, although lacking some wriggle room for toes under the front seats. The whole interior is beautifully finished, comprising light grey leather around much of the cabin, with double-stitched charcoal leather for the dash top, and textured metal-look decorative trim and black alcantara for the pillars and headlining.

SAFETY?

BMW has specified a mix of aluminium with high-tensile strength and ultra-high-tensile strength steels for the construction of the M5, with crash safety enhanced by the way the materials have been incorporated in load-bearing structures and "precisely defined" deformation zones around the rigid passenger safety cell.

While the M5 hasn't been tested in isolation, its crash safety will correlate to the five-star Euro NCAP rating for other 5 Series-based models.

COMPETITORS

Let's suppose for a moment that there are buyers out there — as indeed they certainly are — for a staggeringly high-performance sedan of generous proportions, but without a lot of outward presence.

Against the M5, those buyers would probably consider the Audi RS6, the Jaguar XF-R and two Mercedes-Benz models, the E 63 AMG and the CLS 63 AMG.

The Audi has a lot going for it — not least of all its quattro traction — but is due for replacement by a new model, one that ditches the lusty V10 shared with Lamborghini for a new V8. And guess what? Like the M5, it's rumoured the V8 in the next-gen RS6 will be twin-turboed.

There's no word on the torque for this new Audi engine, but speculation has it that the new RS6 will offer a whole 2kW more power than the new M5. And furthermore, it is also expected to go for a seven-speed dual-clutch transmission just like the BMW's.

For its part, the Jaguar is tens of thousands of dollars cheaper than any of the German cars mentioned here. Slower to 100km/h (4.9 seconds), the XFR develops less power and torque than the German cars, but it comes with the worthy and venerable six-speed ZF automatic transmission.

That might sound like a shortcoming in light of the seven-speeders of its rivals, but the ZF has proved itself to be durable and refined in the past — and it's likely buyers may prefer its no-nonsense manners to the occasionally capricious ways of the dual-clutch transmission in the M5.

Another point scored by the Jag is its styling, which is more likely to tempt buyers away from other exotics around the same price point than its German rivals. Of the Germans, the M5 arguably comes closest to the svelte style of the XFR.

The E 63 AMG is probably furthest. Smashing to smithereens any preconception that an aerodynamic car must also be a smooth one, the E is angular around the front with prominent, sweeping sculpture lines along the side.

Buyers of the E 63 are likely drawn to it by its 5.5-litre twin-turbo V8, which develops 386kW and 700Nm. Despite its extra litre of engine displacement (it's actually 1.1 litres, but Benz isn't fussy about rounding numbers right of the decimal point), the E 63 is slightly more economical than the M5 and is also slightly faster to 100km/h.

Benz's CLS 63 AMG is powered by the same engine as the E 63's. It's the most expensive competitor to the M5, but not by that much…

In a couple of ways it's a close-run race between the CLS and the M5. For acceleration the CLS matches the M5 (4.4 seconds to 100km/h), but the M5 is very slightly more economical than the CLS (9.9 versus 10.0L/100km). For little things such as the difference in refinement — BMW prefers to let you hear the turbos working, Benz doesn't — and not so little things, like handling for instance, the M5 seems to have a slight lead.

Unlike the case of the Mercedes-Benz CLS 63 AMG that motoring.com.au recently drove in Germany and previously at Albert Park, BMW engineers have not tried to remove all trace of turbo noise from the M5's V8. On boost the turbos whistle away in a melodic counterpoint to the bass riff from the exhaust.

It's not all about refinement, however; the arrival time at Point B — 400 metres away — comes up sooner than before and yet the V8 provides an easier, more accessible driving experience in any other situation as well.

The M5's engine drives through a seven-speed dual clutch transmission, which is efficient and capable, whether the car is being driven to conserve fuel or blatting past a line of slower cars in an overtaking manoeuvre. If there's one qualifier, it's the transmission's occasional reluctance to change gear or release a clutch.

Some thinking time can be required when the driver demands instant acceleration. In fairness, it's something noticed in the 5.5-litre Benz AMG models also.

Further to the M5, straight line performance won't come immediately from kicking down the transmission, which will select a lower gear, but not necessarily the one the engine needs to get into the thick of it. Indeed, at times the transmission can be surprisingly slow to respond, even with drivetrain, suspension and steering all tuned to Sport+. It can also be a little clunky at times, especially driven assertively without the driver lifting the right foot.

For drivers accustomed to the gentle slurring of a conventional automatic as the unit shifts up a gear, the M5's upshifts will come as a shock (actually a short thump in the back) when set up for the track. An unusual aspect of the transmission, which BMW refers to as DKG DriveLogic, is the lack of a Park function, per se. When the driver is ready to leave the car standing, simply shift the transmission to neutral, actuate the electric parking brake and turn off the engine.

The transmission channels the engine's 680Nm of torque to the rear wheels through BMW's Active M Differential, which works together with the car's electronic traction control to let the torque flow freely without the car getting ragged.

On Spain's roads — sealed with a compound of bitumen and marble apparently — traction was easily overpowered by the sheer torque of the M5. There's nothing to focus the mind quite like pulling out to overtake only to find the traction control light blinking at you and only about half the car's performance potential available! Hopefully the problem won't be evident on our woefully maintained but high-friction country roads.

Fuel consumption, according to the M5's trip computer was as low as 11.2L/100km, although when the car was given some stick on the roads of southern Spain the fuel consumption rose to 14.2L/100km. After 12 torrid laps of the privately owned Ascari racing circuit the fuel consumption readout was showing 21.2L/100km average. Taken in context that's not a bad effort against similar cars from the recent past.

The M5 can be placed quite precisely in corners and the steering response is good in the context of a large luxury sedan that basically occupies most of the lane on Spain's country roads.

Ride was firm in Sport+, but not unforgivably so. As with many prestige cars offering adjustable ride comfort, the M5 rolls over the top of irregularities in the road, rather than crashing through them. In Comfort mode the M5's ride quality is much improved.

Brakes, when stomped on hard, will transmit an audible hum to the cabin from the cross-drilled rotors, but are powerful and highly dependable, based on the writer's experience at Ascari.

The Active M Differential and the programmable suspension, steering, drivetrain and safety nannies all proved their worth on the Ascari circuit. Exiting a corner is where the whole bundle of electronic dynamic driving systems can make a real difference. Very few cars can deliver this level of response and feedback to the driver's demands. The M5 is an easy car to drive around a racetrack and flatters the driver, but the corners of Ascari were also properly cambered and provided an essentially benign backdrop that suited the M5's dynamic traits.

The six laps at Ascari helped to formulate an overall picture of the big BMW's cornering dynamics — and on the road also. After a couple of laps it was quite clear how far to squeeze the throttle for the optimum exit speed, without the tail stepping out and the car dropping further behind the pace car in front.

As the writer became familiar with the circuit and the car, the speed climbed and the exit speeds from the corners began to influence the whole plan of attack for the circuit. It became clear that there was only one corner in the entire 5km length of the track that required second gear — the rest was third or higher.

An exit from a particularly wide and long left-hander was practically on top of the braking markers for a tight left-hander. If the BMW wasn't quite straight, the commencement of braking would lift the tail and the driver would carry a little more speed into the hairpin than was entirely desirable. In that event, the M5 was more likely to oversteer into the corner on a trailing throttle — rather than understeer. In fact, understeer was only evident to this reviewer on the exits, and then with with immoderate applications of power.

The M5, in the tighter stuff, could feel like a heavy touring sedan, but no more so than the CLS 63 AMG driven at Albert Park back in March. They're two cars in a very similar mould — long-legged tourers for four rather than out-and-out sportscars. There was less time to check at Ascari — an interesting track without Albert Park's long straights — but the M5 was easily exceeding 200km/h in short straights, just as the CLS did in Melbourne.

Not altogether surprisingly, all four tyres were demonstrably scuffed after the return from Ascari.

So the results are in: a circuit like Ascari is where the M5 really shines. In Australia, blocked in by B-Doubles on the freeways and courier vans in the suburbs — those aren't the places for the M5. It's a car that really deserves to be given more room to move.