BMW has slotted its 3.0-litre twin-turbocharged oil-burning engine into the 6-Series - and revised the entire range at the same time.
On sale in September, the facelifted coupé and convertible models will be available with the 286bhp straight-six unit for the first time, making the 6-Series the only car in its class to run on diesel power.
The newcomers are badged 635d, and promise impressive performance. The coupé covers 0-62mph in 6.3 seconds and achieves 40.9mpg combined economy, while the cabrio completes the sprint in 6.6 seconds and returns 39.2mpg. Both are electronically limited to maximum speeds of 155mph.
The diesels get a revised six-speed automatic box, which also appears in the fresh petrol models: the 272bhp 3.0-litre petrol-engined 630i and the 367bhp 4.8-litre V8-powered 650i. The latter are more economical by 15 per cent and five per cent respectively, thanks to the addition of a new brake energy regeneration system. All variants get a revised look with tweaked headlamps incorporating LED running lights, a smoother lower bumper with restyled air intakes and new kidney grilles. At the rear, the boot shape has been softened and now features an integral central brake light. LED tail-lamps complete the changes.
Inside, there are new materials and colours for the dashboard and upholstery, while the iDrive cabin control system has been updated to include a row of eight 'favourite' buttons on the centre console. Prices have yet to be revealed, but the revised 6-Series range is expected to rise slightly from the current starting point of £47,975.
Meanwhile, BMW has introduced its Efficient Dynamics systems across the 3-Series line-up to improve economy. That means all petrol models are now fitted with fuel saving direct-injection technology. Brake energy regeneration - which recovers heat energy during braking - is also added, while an automatic stop-start feature is available on all four-cylinder cars.
