A new era for this executive bahnstormer
FUTURE MODELS/ BMW’s flagship M sports sedan is clawing back into the fight with all-wheel drive, writes Michael Taylor
BMW M’s main sports sedan weapon is back, packing a 3.4second sprint to 100km/h to hurl itself back into the fray against Mercedes-AMG, Audi Sport and Jaguar when it arrives in SA in the first quarter of 2018.
Blasted out of the sports sedan race front lines by AMG’s E63 and Audi Sport’s RS6 and RS7, the overweight, undergripped M5 has given way to a sixth-generation, all-wheeldrive rocket that’s capable of 305km/h. The biturbo 4.4l V8 engine has been significantly upgraded, but it’s the switch to all-wheel drive — a move BMW once insisted would never happen with M’s core models — that looks set to steal the show.
Besides slashing a second from the 100km/h sprint time of the outgoing M5, the new model now blasts out to 200km/h in 11.1 seconds and is officially limited to 250km/h, though that can be raised to 305km/h with the Driver’s Package.
While it always fires up in allwheel drive, the fully active layout means the driver can switch it into rear-wheel drive at will, and its skid-control system can also still be fully disengaged, meaning the M5 can be drifted as long as the driver’s skill and tyre budget lasts.
Even in all-wheel-drive form, the M5 only brings its front tyres into play when the rear tyres have exceeded their longitudinal traction limits, using a system that combines the xDrive active all-wheel-drive centre differential with the active M Differential on the rear axle. The drivetrain’s rigidity techniques have been reinforced to cope with the extra torque when the car is switched to rear-wheel-drive mode.
M claims the 4.4l V8 engine is heavily revised and “more potent than ever”, but it reads like it has been lightly revised and has the same 441kW power output as the outgoing F10 M5’s strongest version.
The power peak arrives between 5,600 and 6,700r/min, while the 750Nm torque peak hits at 1,800 and sticks around until 5,600r/min, so there’s complete performance curve overlap on the spec chart. There’s another 70Nm of torque on offer over the stock versions of the F10 M5, though.
The changes to the powerplant include a boost to fuelinjection pressure to lift it to 350 bar, delivering shorter injection times and M claims that is better for atomisation of the fuel and better for throttle response.
That said, it continues with an 88.3mm bore and an 89mm stroke, giving it a swept capacity of 4,395cc, but what sets it apart, still, is the way it funnels its exhaust gases out of the combustion chambers and out to the open sky. It retains the outgoing car’s cross-bank exhaust manifolds, which make better use of the exhaust gas to spin up the turbochargers than the usual system, plus there is a Helmholtz resonator between the dual-branch exhaust system’s two silencers to lower weight.
It now uses indirect intercooling and it has picked up a mass. The first E28 M5 in 1989 weighed less than 1,500kg and every M5 has added weight at each generational change.
It has also ditched the dualclutch transmission in favour of an eight-speed automatic, capable of both smooth, cruising shifts and paddle or gear levershifted manual gear changes.
Like most M cars, the M5 is wider in the wheel arches than the standard version of the car and it still occupies 4,965mm of road length and 1,903mm of width. It’s 1,473mm high, too, but the more important stats are that the wheelbase is 2,982mm and the front and rear tracks are 1,626mm and 1,595mm.
The grip potential isn’t just helped by the enormous footprint but a stiffened body structure at both ends, including strut tower-to-bulkhead stiffening and tower-to-front struts at the front end.
A key change is the unloved, wooden, slow hydraulic steering has been replaced by an electro-mechanical steering system and, thankfully, it’s hard to imagine it being any less appropriate for a high-performance car than the outgoing system.
STEEL BRACE
The rear end is modified from the standard 5-Series’ five-link system, but takes on new toe links and more rigid rubber mounts, plus elastomer bearings, stiffer anti-roll bars and stronger lower wishbones. There is also a steel x-brace beneath the rear bodywork, plus a transverse aluminium strut.
Inside, the M5 runs to a headup display and its rather cluttered steering wheel has new, red, M1 and M2 buttons to give its drivers easy access to their customised engine, transmission, suspension and skidcontrol modes.
The standard anchors are compound steel, with bluepainted six-piston fixed calipers on the front and single-piston floaters on the rear. They can be upgraded to carbon-ceramic units at the touch of a credit card, saving another 23kg.
There is a new front bumper and apron area, designed to feed cooling air into the brakes and the engine’s intercoolers and radiator, while there is a diffuser in the rear, flanked by four exhaust pipes, which retain their flap control to make them louder on demand.
Scheduled for launch at the same time as the standard M5 is the BMW M5 First Edition. This special edition version — limited to a run of 400 examples worldwide — has BMW Individual Frozen Dark Red Metallic paintwork, is exclusively appointed and costs a hefty whack over the regular model.