GERMANY: BMW drop-top 4th on 1 theme

By just-auto.com editorial team | 2 October 2007

BMW's new small convertible due out globally soon, is the fourth variation on the several-years-old 1-series theme (after five- and three-door hatchbacks and the coupe first shown last month at Frankfurt).

BMW said it is the "world's first premium convertible in the compact segment" and it will have four- and six-cylinder engines, from the entry-level 143hp I4 118i convertible to the tantalising I6 306hp 135i.

Unlike the 3-series drop-top, which now has a folding hardtop and, further up the range, a Porsche Boxter-rivalling price, the 1-series has a fabric roof that electro-hydraulically opens or closes in 22 seconds, and at speeds of up to 25mph.

It is available in black, beige or, as a claimed world first, in an anthracite silver fleck which is a fabric material interwoven with fine shiny metallic fibres.

Like coupé models, the 135i convertible has the M Sport aerodynamic package as standard.

The car seats four occupants and has 305 litres of boot space with the roof up (260 litres lid down) and, like the 3 and 6 series convertibles, those choosing hide for their seats will get BMW's new SunReflective leather technology that uses 'cool pigments' during production to reflect infrared rays of sunlight. This is said to reduce the surface temperature of the seats by up to 20 degrees C compared to conventional leather upholstery.

Borrowed from the 3 series convertible are specific settings for the air conditioning system. Alongside the standard 'gentle', 'medium' and 'intensive' settings, the system recognises when the roof has been opened and defaults to a 'convertible' mode. In this situation, the ventilation control reacts less to the interior temperature and more to the outside temperature and sunlight factors to set the intensity of the ventilation supplied.

Safety equipment includes two roll-over bars that employ with the air bags to extend from behind the rear seats in a fraction of a second.

Other technology under BMW's new EfficientDynamics banner includes brake energy regeneration, intelligent alternator control and an absorbent glass mat battery to harness engine power that would normally have been lost during engine over-run or braking. An optimum gear shift indicator is standard on manual gearbox cars.

All models feature a new, clutched air conditioning pump that decouples when not needed and uses only 200 watts, or 10%, of the normal power needed to drive a conventional pump. All other than the 135i have electronic power steering that, compared to conventional hydraulic power steering, operates on an 'on demand' basis, reducing engine output normally needed to power the hydraulics.

All four-cylinder manual transmission cars have auto start-stop as standard.