The story of the new Bentley V8 engine goes back to 2008 with the Bentley company’s decision to look for a 40 per cent improvement in fuel economy and emissions without sacrificing performance.
The powertrain is a joint development with Volkswagen group stablemate Audi. Just how has that 40 per cent reduction been achieved?
Head of power train development at Bentley Paul Williams had a list:
- Downsizing the from a 12-cylinder engine to a V8 accounts for 16%
- The new 8-speed ZF transmission, 6%
- Cylinder de-activation (transition from V8 to V4 mode under light throttle load), 5%
- Variable power steering, 3%
- New Bosch engine management, 3%
- Reduction in weight and drag, 2.5%
- Thermal management, 2%
- Lower rolling resistance tyres, 1%
Williams added: “We’ve maintained the performance by using high pressure twin turbochargers and direct injection for the first time in a Bentley. The 8-speed transmission has a number of benefits, optimising engine speed, giving a smoother and faster gear change and it is capable of switching multiple gears in one go – dropping from 8 to 4, for example, when you require fast acceleration.
“We have also spent a lot of time tuning the exhausts to give the notes that people want, starting with a typical V8 burble at idle, moving to a mid-range growl and finally a high-end howl.”