Revealed and driven: New BMW M5 packs 717bhp hybrid V8

The seventh-generation version of BMW's ’bahnstorming super-saloon makes the landmark switch from pure petrol power to an electrified system with total outputs of 717bhp and 738lb ft – far above those of any previous iteration.

That’s enough punch for 0-62mph in 3.5sec and a top speed of 189mph in derestricted Driver’s Package guise. The M5 uses a new high-revving (7200rpm), 577bhp twin-turbocharged 4.4-litre V8 and a 196bhp electric motor inside an eight-speed automatic gearbox, in a set-up familiar from the M division’s first PHEV, the XM SUV.

The M5’s outrageous pace comes in spite of a dramatic increase in bulk to around 2400kg. The chunky 18.6kWh drive battery (which provides 42-43 miles of electric-only range) contributes to an uplift of nearly 500kg over the previous, pure-V8 M5.

The M-fettled chassis – with the suspension, steering and structural components all uprated over the standard 5 Series – is equipped as standard with adaptive suspension, a bespoke M differential and a rear axle that can steer up to 1.5deg to boost manoeuvrability and stability.

The cabin is more familiar from the standard 5 Series, but there are bucket seats, lashings of carbonfibre trim and a bespoke control panel for adjusting the driving modes.

There are also physical controls for a raft of performance-focused functions, including a lap timer and launch control.

Order books are open now ahead of production beginning in November.

So you've now seen the new BMW M5 uncamouflaged – and boy oh boy, is there a lot of it to see.

The G90-generation M5 is the first M5 to stretch beyond five metres in length. And in terms of width? Compared with the already expansive 5 Series on which BMW’s latest super-saloon is based, the wheel arches are swollen by 75mm at the front and 48mm at the back.

Had such a car been released a few years ago, it wouldn’t have been an M5 but an M7 – the one product M division has never even attempted. As for weight, we will get to that topic in a moment, but it’s the most eye-widening statistic of them all.

Yet if M division has made an art from anything in recent memory, it’s making chunky cars feel great to drive. Take the current M3 Competition. This big-nostrilled beast hogs more of the road than a 3 Series has any right to. It also weighs 100kg more than any of us were expecting. But so too is it a masterclass in exploitable handling.

Anyone who tells you the M3 of the previous generation – usefully smaller and far lighter, sure – is a sweeter-handling car probably hasn’t experienced both. You would be a fool to bet against M division pulling off the same trick with this supersized, hybridised M5.

Rewind to the Salzburgring in mid-May and our first chance to get a read on the hottest ever Fünfer. We have pre-series cars to try briefly and some engineers to talk to. As pre-series cars, rather than prototypes, these camoed cars are “95%” finished.

It means there’s no going back in terms of hardware but there may yet be some calibration tweaks. For example, to the rear-axle steering – new to the M5 toy box – or the specific way in which the 196bhp electric motor between the 4.4-litre V8 engine and gearbox can pre-decelerate the crankshaft for faster upshifts or accelerate it for snappier downshifts. But in the main, this is it: your seventh-generation M5.

Getting up close and personal to the cars in the pit lane confirms what the numbers suggest. The new M5 has a monolithic, intimidating presence. It isn’t simply big in absolute terms – it seems bigger still than it actually is, due to there being deliberately less detail in its tectonic-plate-sized body panels.

Even the little ‘M5 blade’ behind the front wheel has been ditched in the culling of “small, sophisticated” parts. A grizzled gamekeeper once described a lion to me simply as “200 kilos of fast-twitch muscle fibre attached to a pair of jaws”. This M car is the machine equivalent: an almighty grille and four exhaust pipes bookending 717bhp of V8-hybrid muscle.

Standing next to me in the pit is Bernd Barbisch, lead powertrain engineer. Asked if swapping V8 for straight-six power might have trimmed some of the M5’s inordinately tubby 2400kg or so, he says downsizing was “not an option”. Had they instead used a hybridised version of the 3.0-litre engine from the M3, it would have saved only 50kg. In any case, the feeling in Garching was that a twin-turbo V8 is now integral to the modern M5 character. Fair enough.

Alone, this S68 unit makes 577bhp. Yep, less than the S63 in the old M5 Competition. However, in this state of tune it’s futureproofed for emissions standards, with the motor plugging the shortfall in grunt. Less forgivable is that the overall power-to-weight ratio of the old M5 is still superior. Ouch.

The scale of this new plug-in hybrid powertrain hits home when Barbisch confirms that there was no chance in hell they would have been able to shoehorn it into the old M5, which was hardly an Isetta.

The eight-speed automatic transmission is carried over from the regular 5 Series, albeit with strengthening measures that not only allow for the M5’s top speed of 189mph but that also prevent it from disintegrating when presented with 738lb ft of torque. That isn’t a hollow claim. The torque converter of the old M5 CS was already just about at its limit, and that only had 553lb ft to deal with. The crown wheel inside the rear differential has also grown 10mm and is now of dinner-plate proportions. Its diameter of 235mm is in the world of diffs simply massive, says Barbisch.

Downstream of it is the most expansive contact patch ever lavished on an M5. The 285-section front tyres are the same size as the rears on the old M5 CS; the back is shod with 295-sections. There will be a broad choice of rubber, but dynamics chief Klaus Huber would prefer it if you went for either the Michelin Pilot Sport S 5 or the new Pirelli P Zero R. He says both generate a touch more precision that will be noticeable on the road.

Road impressions will need to wait. For now, we’re confined to the fast, bumpy Salzburgring. Dirk Hacker, BMW’s avuncular R&D chief, leads us out of the pits in an M4 CS. As a PHEV, the M5 has an 18.6kWh battery slung low between its axles. That will yield 40 miles or so of electric-only range and means you will pull off the mark silently. Today the silence doesn’t last long, because Hacker isn’t hanging about.

The first thing you notice is the torque fill. Although comparatively relaxed in its tune, this V8 doesn’t exactly have a blindspot in terms of oomph at low crankspeeds, but improved throttle response and that electrically boosted, synthetic-feeling pick-up in propulsive force is unmistakable.

Elsewhere, the driving position is predictably excellent but the hip point feels high and the seat design isn’t as good as before. The old seats, with their independently adjustable upper backrest, were among the best in the business. Our car’s dash is buried under felt cladding, so for now there’s not a lot more to say. The hint of SUV-ness in the sheer scope of the cockpit is none too welcome, though. The steering is heavy, too. It all builds a picture.

Two big elements stand out. The disconcerting speed of the new M5 – and its weight. It’s nearly half a tonne heavier than the old M5, and the reality of that can never truly escape you. However, this isn’t to say this car is wayward or dim-witted – oh no. Huber promises that its apex speeds are “easily” superior, and I can believe it.

To deal with the extra grip, the front portion of the body-in-white is considerably stiffer than before and the double-wishbone suspension is revised wholesale, both in terms of its fundamental kinematics and the nitty-gritty elastokinematics. There’s quite a bit more negative camber now. M division has also changed its damper supplier (from Sachs to Bilstein), and for the first time the M5 uses progressive springs, found on the back axle. It has also stuck with passive anti-roll bars, rather than active ones, for more linear, natural body roll.

Hacker still has his foot down in the M4 CS, but by now he must be beginning to feel like a Cessna with an Antonov on its tail. The M5 not only gets that bloated nose into corners fast (and, it must be said, with a delicious, zinging accuracy that totally belies its kerb weight) but also then summons exits of an explosivity that, back in the UK, I’m certain will make even sweeping A-roads feel quite poky at times.

Through Salzburgring’s chicane and esses, I can tell that Hacker is working reasonably hard to keep up his speed. Meanwhile, our M5 can effortlessly slog itself right onto the backbox of the more junior M car at will, such is the depth of its mid-range performance. Huge grip, too.

This M5’s issue certainly isn’t supersonic travel, then. Neither is it core handling behaviour. After our drive, Huber, in a contender for understatement of the year, says that avoiding understeer is “important for us at M”. And of course he’s right. On track, the M5 has an obvious pedigree balance and that sweet, M-typical cohesiveness in the association between steering input, body roll and attitude.

It will be an intuitive thing to drive, but only in spite of its vast weight and girth, which will sap some joy out of the driving process, as well as usability – always a key M5 trait. What magic there is in this thunderous car resides in what M’s engineers have achieved in the face of developments outside their orbit.