What's all this about?

This, according to Bentley, is the new 'fourth-generation' Flying Spur (as in, post-2005 modern-era Spurs). However, it's clearly a revised version of the magnificent third-generation car, but the interesting news here is that it now has a plug-in hybrid (PHEV) drivetrain.

No, hang on a second - this Spur has already had a PHEV drivetrain, hasn't it?

Yes, a V6-derived iteration, but that was previously a third powertrain choice for the Mk3 Spur alongside the mega 6.0-litre W12 and the 4.0-litre biturbo V8. However, both of those 'pure' combustion powertrains have now, sadly, bit the dust, so the only way you can own a brand-new Flying Spur is by specifying a PHEV of some sort. Pleasingly, this latest announcement pertains to the new 'ultimate performance hybrid' powertrain that has already been confirmed for the latest Continental GT. It's a system related to the set-up in many of the most powerful Porsche PHEVs.

Aah, so it's a V8-based hybrid?

Got it in one. More specifically, it's a V8-based PHEV that has 19 per cent more power and 11 per cent greater torque than even the mightiest Spur derivative of the old W12, the Speed. Hence Bentley will be marketing this new Flying Spur V8 PHEV as the 'Speed' this time around.

To save you the maths of working out those percentages on the previous W12 Speed's 659hp and 900Nm outputs, it means the new V8 hybrid Spur conjures up massive peak figures of 782hp and 1,000Nm. This makes it easily Bentley's most powerful saloon ever put into production and allows the Crewe-based concern to tout the Spur PHEV as the 'four-door supercar'. It generates those numbers from a 600hp/800Nm 4.0-litre biturbo V8 and a 140kW (190hp) electric motor working in tandem, allowing it to run 0-62mph in just 3.5 seconds, but there's also a 25.9kWh battery pack which can provide 47 miles of all-electric running in the Bentley - the company says that if you brim the tank and fully replenish the battery, you've got around 515 miles of cruising range from this leviathan.

Full fuel consumption and CO₂ figures have yet to be finally homologated for the new Flying Spur Speed PHEV, but expect them to easily surpass anything we've yet seen from any Spur bar the V6 Hybrid. And it'll probably beat even that car, because it used a smaller 18kWh power pack. Anyway, not only does the V8 model have nearly 50 miles of EV range, but the Flying Spur Speed also no longer needs cylinder deactivation on its 4.0-litre V8. After all, why shut off only half of the cylinders in the engine when the whole octet can be powered down while propulsion is left to the e-motor? To which end, you can drive the Bentley at speeds of up to 87mph and with a maximum of 75 per cent throttle inputs, all without waking the eight-pot, while recharging the car takes 15 minutes shy of three hours, courtesy of an 11kW AC ceiling charge rate.

Hmm, is the new PHEV Spur Speed all straight-line pace and on-paper eco-goodness? Can it handle?

Absolutely. Bentley fits it with the Performance Active Chassis, which includes Bentley Dynamic Ride (powered, active anti-roll bars) for greater body control, all-wheel steering for increased agility and manoeuvrability, an electronically controlled limited-slip differential, and twin-valve adaptive dampers with three drive modes (Comfort, Bentley and Sport). The British company also claims this PHEV Spur has a 48.3:51.7 weight distribution, which is impressively balanced.

And how about the exterior and interior?

Speed-specific touches include the front and rear bumpers, as well as that mesh-pattern radiator grille. The Styling Specification aerodynamic package will now be finished in body-colour on the Flying Spur, although customers can opt for a carbon-fibre kit. There are three designs of 22-inch alloy wheel for the V8 PHEV, one of which is a new ten 'swept-spoke' rim in either bright-machined grey or painted black.

Within, there are redesigned seats with 3D diamond quilting and a new perforation pattern for the hide centres, while the usual exquisite level of Bentley craftsmanship continues - as does the majestic Bentley Rotating Display option, which mounts the 12.3-inch infotainment screen on a huge rotating prism in the centre of the dash (other faces include wonderful analogue gauges, or some plain veneer to match the rest of the fascia). But the company is also keen to stress that buyers have 'tens of billions' of possible configurations for the Flying Spur Speed V8 PHEV as it is, long before you get to coachbuilding division Mulliner and its infinite possibilities for customisation and personalisation.