Bentley downsizes to twin-turbo V8

FEW car-makers can lay claim to ‘downsizing’ to a twin-turbo V8 in order to reduce fuel consumption, but that is precisely what Bentley has announced ahead of next month’s Detroit motor show, where it will unveil its first eight-cylinder Continental models.

The Volkswagen-owned British brand’s new Audi-sourced twin-turbo 4.0-litre V8 will debut in two unique new entry-level versions of the Continental GT coupe and GTC convertible, which open for orders in January before arriving in Australia from mid-2012.

Bentley's new V8 will slot in beneath the Continental's existing 6.0-litre twin-turbo W12 engine and should provide a more affordable entry price to the range when it eventually also powers the Flying Spur sedan, which currently opens the Continental line-up at $374,666 plus on-road costs.

The four-door is the final Continental body style remaining to be renewed – following the release of the second-generation GT here this year and first local deliveries of the redesigned GTC soft-top early next year – For now, Bentley has released a handful of seismic statistics for its new V8, which will join the twin-turbo 6.75-litre V8 seen in the brand’s flagship Mulsanne limousine, and will be differentiated from the W12-powered two-door Continental GT and GTC models by a number specific exterior and interior design elements.

Revealed in images and a YouTube video that shows Bentley development engineers belting a GT V8 around a closed test circuit in the dark at full glorious noise for no apparent reason, Bentley’s second twin-turbo V8 is closely related to the engine that powers Audi’s largest S-badged performance models.

Bentley’s new 4.0-litre V8, which starts life in the same Hungarian engine plant as the Audi mill before final assembly takes place at Crewe in England, slams down no less than 373kW (500bhp) at 6000rpm and 660Nm of torque between just 1700 and 5000rpm.

Although that makes it slightly less powerful (but 10Nm torquier) than the S6, S7 and S8, which produce different power and torque curves, it all but matches the peak power (if not torque) of the Mulsanne’s much larger 377kW/1020Nm twin-turbo 6.75-litre V8.

Combined with a new close-ratio eight-speed ZF automatic transmission, Bentley says the force-fed small-bore V8 can accelerate the all-wheel drive Continental GT to 100km/h in less than five seconds and a top speed of more than 290km/h.

Despite the latest Continental’s GT’s 65kg-lighter but still heavy-duty 2320kg kerb weight (in upgraded 423kW/700Nm 6.0 W12 guise), Bentley says the model’s first V8 delivers an “exceptional power-to-emissions ratio combined with classic Bentley power and torque”.

Crucially, however, the new 4.0 twin-turbo V8 will see Bentley fulfil its commitment to producing a new powertrain that improves fuel efficiency and CO2 emissions by 40 per cent.

Efficiency figures have not been released, but the new V8 – like the Mulsanne’s big-bore 90-degree pushrod single-cam V8 - features direct-injection and cylinder shutdown systems – the latter effectively making it a four-cylinder under light throttle loads - technologies to reduce consumption and emissions and Bentley says the GT V8 models will cover 800km on a single tank.

There is no mention of the E85 ethanol capability (as with the Mulsanne’s V8) or an idle-stop function, but assuming the GT’s fuel tank remains unchanged, the V8 version should therefore consume about 11.0 litres per 100km.

That will make the V8 GT far more frugal but only marginally slower than the W12 GT, which can sprint to 100km/h in 4.6 seconds and a top speed of 318km/h but gulps fuel at 16.5L/100km and emits 384g/km of CO2.

At the same time, the Continental V8s will still be quicker and more economical than the bigger Mulsanne, which consumes 16.9L/100km, emits 393g/km of CO2 and rockets to 100km/h in 5.1 seconds.

Bentley says its own engine management software sees the new V8 transition between V8 and V4 mode seamlessly and imperceptibly, reducing fuel consumption by up to 10 per cent, while the engine also features special low-friction bearings, unique thermal management, an intelligent charging system and in-valley turbo packaging to reduce lag.

Both new Continental V8 models are distinguished on the outside by a gloss black matrix grille with bright chrome surround and divider, a three-segment lower bumper with black air-intakes and body-coloured dividers, dark rear lower valance, twin ‘figure eight’ exhaust outlets and red enamel Bentley winged ‘B’ badges above the front grille, on the bootlid and in the wheel centres.

Inside, the Continental V8s will feature unique new ‘Dark Fiddleback Eucalyptus’ veneer trim, Eliade cloth headlining and pillar trim and a short centre console instead of the W12 model’s through-console.

Both bent-eight models will be available in seven standard exterior paint colours, with the choice of four standard leather colours and a unique two-tone leather colour split and, for the Continental GTC, three hood colours.

The V8s are available with exclusive 21-inch six-spoke Diamond Black alloy wheels as an option over the standard 20-inch wheels.

“With the new 4.0-litre V8 engine we are widening the appeal of the latest generation of Continentals, introducing a completely new driving experience,” said Bentley Motors chairman and chief executive Wolfgang Dürheimer.

“The new engine will have all the exhilarating power, drama and performance you would expect from a V8 engine sporting the famous Bentley wings, effortlessly delivered with our characteristic 'wave of torque'. This is complemented by innovative powertrain technology that delivers exceptional fuel efficiency and emissions.”

More than 50,000 Continental models have now been sold since 2003, all of them powered by the 6.0 W12.

The GT has attracted more than 23,000 buyers globally – more than the 16,000 cars the Bentley marque managed in the 80 years preceding its arrival.

It has found more than 250 Australian homes since being launched here in January 2004 as the first body style to emerge from the British brand’s Mid-Size Bentley (MSB) platform.

Bentley expects to deliver up to 90 new Continentals in Australia this year – up 50 per cent on 2010 sales.