BMW's forthcoming 2.0-litre turbocharged four-cylinder powerplant will appear in the X1, Z4 and 5

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.

Read more about the new BMW 6-series from the Detroit motor show

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.

See all the latest BMW reviews, news and video

Greg Kable

Add your comment

Log in or register to post comments

Find an Autocar car review

Driven this week

  • 2016 Audi A3 Sportback e-tron UK review
    First Drive
    29 September 2016
    First UK drive finds the facelifted A3 Sportback e-tron remains a first-rate plug-in hybrid that is packed with tech if a little short on driver appeal
  • Citroen C11.2 Puretech 82 Furio
    First Drive
    29 September 2016
    Citroën's city car gets a new sporty-looking trim level, adding visual adornments, but no premium for the 1.2-litre Puretech triple we're driving
  • Mercedes C350e Sport
    First Drive
    28 September 2016
    Petrol-electric C-Class is a surprisingly well-priced alternative to a diesel but not the greatest example of the new ‘PHEV’ breed
  • Car review
    23 September 2016
    Aston kicks off its ‘second century plan’ with an all-new turbo V12 grand tourer
  • Ford Ka+ 1.2 Ti-VCT 85
    First Drive
    22 September 2016
    A rounded, refined and well-sorted bargain supermini – once you’re used to the confusing role redefinition imposed on the once-cheeky Ka