THE new version of BMW's Z4 roadster will cost from £27,610 to £45,795 when it hits the streets in March.

Currently the German brand's only two seat drop-top, the Z4 now comes with a new entry-level sDrive18i model plus a Pure Traction Design package boasting a level of specification not previously seen on a Z4.

The sDrive 18i uses a de-tuned version of an existing 2.0-litre turbocharged engine. Producing 156bhp, it can hit 62mph in 7.9 seconds and on to a top speed of 137mph, while Combined fuel economy is 41.5mpg and emissions 159g/km.

Some of the existing engines have also been improved, including the most popular derivative - accounting for 80 per cent of sales - the 184bhp sDrive20i that achieves 41.5mpg and 159g/km of CO2.

Further up the range the turbocharged sDrive28i and the six-cylinder twin-turbo sDrive35i and sDrive35 boast 245, 306 and 340bhp, all with an electronically-limited top speed of 155mph.

Six-speed manual transmission is standard but there's also an optional eight-speed automatic with paddles, while buyers of the Z4 sDrive35 have a seven-speed Double Clutch Transmission, again with gearshift paddles, as standard.

Design wise the changes are minimal, the headlights now including white LED corona rings and a white 'eyebrow' with chrome detailing, while in profile the side gill features chrome details and LED side repeater lights.

The Pure Traction Design package, available exclusively in Valencia Orange with optional black contrast roof and costing between £550 and £2,240, brings Sport seats in Alcantara and leather with contrast stitching, Anthracite headlining and a unique metal weave interior trim.

Standard equipment across all models now includes DAB radio, Xenon headlights, Bluetooth, USB connectivity and Sport multi-function steering wheel. All models apart from entry level sDrive18i SE come with leather upholstery.