BMW reveals the M Power-lite Z4 sDrive35is

We should be feeling celebratory when BMW launches a 330bhp rear-wheel drive sportscar with twin-clutch transmission, adaptive suspension and specially tuned exhaust, but somehow we find ourselves thinking about what could have been.

Surely every one of us is wondering why the M3’s 420 bhp V8 power plant wasn’t the automatic choice?

Making its world debut at the 2010 North American International Auto Show (NAIAS) in Detroit, the Z4 sDrive35is begins production in Spring 2010.

Power has been increased to 335 PS, 35PS more than the sDrive35i and torque has risen to 332 lb-ft from 1,500 rpm to 4,500 rpm. The upgraded engine management system of the BMW Z4 sDrive35is includes an electronically-controlled over-boost function to briefly increase torque under full load by another 37 lb-ft. This temporary torque peak of 369 lb-ft gives the car a significant increase in acceleration, enabling the BMW Z4 sDrive35is to complete the sprint from a standstill to 60 mph in just 4.7 seconds. Top speed is limited electronically to 155 mph.

Fuel consumption and emissions are expected to match that of the sDrive35i, when fitted with the Double-Clutch Transmission (DCT).

The exhaust system of the BMW Z4 sDrive35is has been tuned specifically to enhance its sporty feel. Acoustic engineering gives the car a very unique sound pattern across the speed range, which is the result of special baffles and a unique set of silencers. The sound is said to be characterised by a deep rumble with a focus on the low frequency sound range.

The Electric Power Steering (EPS) on the BMW Z4 sDrive35is has been reprogrammed to improve steering feedback and turn-in precision, however the real news is that BMW’s 7-speed Double-Clutch Transmission (DCT) has been fitted for the first time to a model outside of the M3 range.

Using a dual-mass flywheel the DCT can shift gears without the slightest interruption of power to the rear tyres, and offers a choice of automatic or manual gear selection. The DCT system in the sDrive35is features a launch control function for use when accelerating from a standstill, and is operated by an electronic gear selector on the centre console or gearshift paddles on the steering wheel (although using the up-down format of conventional BMWs rather then the Left-Right system of the M3).

The BMW Z4 sDrive35is includes the new M Sport upgrades such as M Aerodynamics and adaptive M Suspension. The adaptive M Suspension combines a ride-height reduction of 10 millimetres with electronically controlled shock absorbers (Dynamic Damping Control) to improve the roadster’s agility without compromising ride comfort. The M Sport upgrades package has been designed to emphasise the Z4’s athletic character through aerodynamically optimised exterior features and customized interior components.

The BMW Z4 sDrive35is is available with a choice of six paintwork colours. In addition to Alpine White and the metallic colours Titanium Silver, Black Sapphire, Space Grey, and Deep Sea Blue, the Z4 Roadster is now available for the first time in Melbourne Red metallic. Regardless of the colour chosen, the exterior mirror caps on the BMW Z4 sDrive35is are always Oxide Silver.

Inside the BMW Z4 sDrive35is features a new thick-rimmed M leather steering wheel with gearshift paddles, an M driver’s footrest, sport seats and grey-faced instrument dials featuring the “sDrive35is” model designation. Further interior enhancements include M door sill strips, floor mats with coloured piping and the “sDrive35is” model designation, as well as an M interior trim in Aluminium Carbon.

Whether BMW will ever fit its M Power V8 engine to the Z4 remains a mute point, with M Division’s focus now on forced induction powerplants (the next M5 is said to use a high-revving twin-turbo V8), then perhaps this Z4 sDrive35is represents the shape of things to come.

Let us know what you think.