We like
Beefy torque delivery, zero turbo lag, price and value, desirability

Room for improvement
Substantial weight gain, jerky dual-clutch transmission

AFTER just a few corners in the new M5 ‘sledehammer’ at Victoria’s iconic Phillip Island racetrack, we had a problem.

BMW boldly claims that its unique, patented induction/exhaust system - cleverly mounted between the M5’s two cylinder-heads – delivers instant throttle response and eliminates turbo lag, the enemy of any accomplished performance car.

Right now, however, the hairy-chested twin-turbo V8’s power delivery feels anything but linear, instead presenting pronounced dips and troughs right across its broad 7200rpm rev range, making the fifth-generation four-door executive express feel anything but predictable.

A quick glance at the instruments soon revealed the power troughs were accompanied by the amber flashing warning light of the seamlessly effective electronic stability control system, which as it turned out had been given a thorough workout by the combination of my lead foot and no less than 680 of Sir Isaac Newton’s finest anywhere between 1500 and 5750rpm.

In fact, despite the near-foot-wide rubber wrapped around huge 20-inch alloys out back, the M5’s ground-trembling new force-fed V8 had sufficient twist to illuminate the car’s ESC activation light almost constantly for an entire lap of Phillip Island, including all the way to about 245km/h on Gardner straight in fifth gear – in the dry.

Fiddling with the car’s two M Drive buttons - which offer a pre-selected combination of steering, suspension damping, transmission, throttle pedal and ESC settings – made little difference, and nor did switching everything manually to ‘sport plus’.

We weren’t brave enough to switch off the ESC entirely at the notoriously high-speed island circuit (where slalom and wet-surface exercises later in the day would demonstrate the M5’s power oversteer abilities), so it became quickly apparent that gently squeezing on the throttle while unwinding steering lock out of turns was the key to quicker corner exits and therefore faster lap times in the M5.

Such is the instantaneous torque delivery of the first turbocharged M5 that even on Phillip Island’s sweeping bends its double-huffer V8 overwhelms the mechanical grip of a formidable chassis that cannot disguise its size and weight, which in this generation gains a sizeable 100kg.

Yes, the latest M5 is safer, more luxurious and better equipped than ever before, boasting an arm-full of extra standard features that, combined with a $12,000 price reduction, makes it $25,000 better value than the E60 it replaces.

More importantly, that also makes it $11,000 cheaper than the E63 AMG, the M5’s most direct large luxury performance sedan competitor from arch-rival Mercedes.

But all this refinement and convenience comes at the expense of weight – the enemy of performance - and, although the big BMW sports sedan sits fairly flat at the limit and handles better than any vehicle this size and weight has a right to, its 1870kg kerb figure is never far from mind when changing direction quickly or barrelling too fast into tight turns.

Ride comfort was surprisingly plush given the big wheels, firm suspension set-up and lack of bodyroll – even over the many corrugations created at the Victorian circuit by the V8 Supercars – but a full assessment of the new M5’s day-to-liveability will have to wait for an extended road test in the real world.

BMW has also done an outstanding job with the M5 brakes, which comprise the largest brake rotors ever on a BMW and although the steering offered plenty of response and feedback, it was never alive in my hands and didn’t inspire confidence when it went light under hard braking on downhill sections like MG corner and the end of Gardner straight.

As the only 5 Series to incorporate a seven-speed dual-clutch gearbox, the M5 lacks the refinement of mainstream models during low-speed manoeuvres and full-throttle up-changes, when a costly sounding thud can be heard from the rear-end – especially in the most aggressive transmission modes.

That said, the multi-mode M DCT auto is nothing like the painfully slow and snatchy sequential manual transmission offered exclusively in the previous M5.

No, we needn’t have worried about BMW’s M division applying a turbocharger to the M5 for the first time, because the latest incarnation of its largest sedan doesn’t take a backward step in the performance department – there is no downside to the bullocking, lag-free torque delivery of its new powerplant.

In fact, with 10 per cent more power, 30 per cent more torque and 30 per cent lower fuel consumption, the twin-turbo bent eight raises the stakes considerably, even if it eschews its predecessor’s spine-tingling V10 shriek for a gruff German V8 engine note.

Yes, the latest M5 is heavier and more luxurious than ever, but it delivers more performance and efficiency than before, bettering the geeky looking E60 and its high-tech, high-revving V10 in all areas.

The F10 also supersedes the previous-generation E39 as our personal M5 favourite, by taking the most successful M5 formula ever – a brawny V8 in an elegantly understated 5 Series body – and adding more grunt, safety and refinement.

Now, if only BMW would produce the ultimate expression of the F10: a stripped-out, lightweight M5 CSL.