BMW gave its new 6-series its public debut in Detroit - but the big drop-top was overshadowed by news of the firm’s forthcoming 2.0-litre turbocharged four-cylinder powerplant, which will appear in the X1, Z4 and even the 5-series later this year.
The 6-series cabriolet will go on sale first, reaching UK dealers in March, with the coupé due to appear six months later.
Two turbocharged petrol models will be available – a 640i with a 316bhp, 3.0-litre straight six, and a 401bhp 4.4-litre V8. BMW confirmed a diesel version will follow but was conspicuously quiet on exactly what form it would take, suggesting an update to the current 630d or 635d motors.
The four-cylinder unit, meanwhile, is being seen as an indirect replacement for the least powerful version of BMW’s classic 3.0-litre in-line six-cylinder petrol engine.
The new direct-injection unit, codenamed N20, is set to make its debut in the new X1xDrive28i at the Geneva motor show in March. The twin-scroll turbocharged motor has a 1997cc capacity but produces 242bhp at 5000rpm and 258lb ft at 1250rpm. That’s 12bhp less but 29lb ft more than the existing X1xDrive28i’s naturally aspirated 3.0-litre straight six and enough to take the new model from 0-62mph in 6.1sec and up to a top speed of 149mph.
Combined cycle fuel economy has been improved by 16 per cent, at an average 35.7mpg, with CO2 emissions down by 33g/km at 186g/km.