Detroit motor show 2012: Bentley Continental V8

Bentley has launched its long-awaited twin-turbo 4.0-litre V8 engine at the Detroit motor show today, saying it promises “an instantly recognisable growl”.

The engine will initially be offered in special versions of the Continental GT and GTC, identifiable by their black grilles, red badges and ‘figure eight’ exhaust pipes. The models will be positioned below existing 6.0-litre W12 Continentals, which will stay in production.

The new V8, which uses direct high-pressure fuel injection and cuts to a fuel-sipping four-cylinder mode on light throttle loads, produces 500bhp at 6000rpm and 487lb ft of torque between 1700 and 5000rpm. Using a new eight-speed ZF automatic transmission, which also improves efficiency, the V8 Continental has a top speed of 180mph, with 0-60mph acceleration below five seconds.

Bentley won’t reveal precise fuel consumption and CO2 figures until early next year. Nor has it said whether the engine has been engineered to run on bio-ethanol, like the 6.0-litre W12. However, it expects V8-powered Continentals to be able to cover more than 500 miles on a single tank of fuel.

The move fulfils a Bentley commitment, made three years ago, to deliver a new powertrain with fuel consumption and CO2 emissions reduced by 40 per cent compared with the W12 engine that has until now powered all Continental models, more than 50,000 of which have been sold since launch in 2003.

The new engine is closely related to the similar-sized unit already used in Audi’s S6, S7 and S8 models, but its power and torque characteristics have been uniquely configured to suit the marque values of Bentley’s cars.

Sophisticated Crewe-configured engine management allows a “seamless and imperceptible” transition to four-cylinder running on light loads. Other technical highlights include special low-friction bearings, thermal management to avoid excess heat loss, energy recuperation via an intelligent charging system and turbo packaging within the engine’s vee to reduce throttle lag.

Q&A with Brian Gush, Bentley Powertrain boss

How similar is your engine to the Audi V8?

"They are related, but producing the V8 was a collaborative effort. Our teams started it together; it helps with big things like sump and block design."

The configuration for Bentley is unique, isn’t it?

"It is on things like this we and Audi went our separate ways. We’ve put the power and torque where we believed they should be to suit our cars."

How much does four-cylinder running boost economy?

"On the European drive cycle, our calculations showed an improvement of about eight per cent. But we did some real-world testing with drivers who hadn’t been told about cylinder deactivation and they returned an improvement of nearly 10 per cent. It’s a big benefit."