Sport automatic gearbox

The new BMW Z4 3.0si comes with a six-speed close-ratio manual gearbox as standard. Those drivers preferring the choice of automatic transmission convenience and manual gearbox involvement will choose BMW's new Sport automatic transmission. Based on a conventional automatic gearbox, a new torque converter and software installation offers a 40 per cent improvement in the gearbox response time compared to a conventional automatic gearbox and a gear change time that is twice as fast.

The Sport automatic system features steering wheel-mounted paddles as a dynamic accompaniment to BMW's traditional Steptronic gear lever. Finally, in common with the sporting pedigree of the new Coupe, this automatic gearbox will blip the throttle on down changes.  



Rigid yet lightweight body and CSL suspension

A key aim for the Z4 engineers was to develop a roadster with the stiffest body structure of any open-topped car. Successfully achieved, the Coupe's foundations were immediately in place and the addition of a fixed roof increased the structural rigidity still further to 32,000Nm/degree. The Z4 Coupe features one of the stiffest body structures of any production car.

And this has not been achieved by the addition of extra weighty bracing. As a consequence, the new Z4 3.0si Coupe weighs just 1,395kgs and the high-performance 3.2-litre M Coupe 1,495kgs - only 10 kilograms more than the Z4 M Roadster. 



CSL inspiration

When the Z4 design team were charged with creating a more sports-oriented car than the Z3, they did have one serious advantage - access to componentry and technology from the inspirational M3 CSL. The new Z4 M Coupe uses the CSL's 345 x 28mm front and 328 x 20mm rear drilled and vented brake discs and high-performance callipers. Suspension components from the M3 CSL, such as the single-joint front axle with McPherson spring struts, forged aluminium track control arms and separate mountings for the springs and dampers, are also used in the Z4 to offer the highest levels of agility and traction.



Steering

The BMW Z4 3.0si Coupe features the electrically assisted Servotronic steering from the Roadster. With its electrical assistance, engine power normally needed to drive a hydraulic steering pump is reduced, equating to a reduction in fuel consumption of one litre per 250 miles. The M division rightly ploughs its own furrow and following many thousands of miles of evaluation on the Nürburgring, engineers from BMW M decided to equip their car with conventional hydraulic assistance. In their expert opinion it offered an even firmer steering feel - perfect for the M experience.



Class-leading safety systems

Keeping the high levels of performance firmly connected to the road is the responsibility of the most advanced traction control and stability system available - Dynamic Stability Control +. BMW's 'standard' DSC system maintains traction by reducing engine power, applying the brakes where necessary and monitoring the yaw angle of the car, bringing it back into line whenever needed. DSC+ has five additional features to provide yet further safeguards and comfort for the driver.

- Brake Pre-tensioning shortens stopping distances by priming the brakes the instant the driver snaps off the accelerator in preparation for an emergency stop. 
- Brake Drying improves braking performance in the wet by periodically applying the brakes to wipe off moisture. 

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