Each team designs its steering wheels individually, taking into account the respective drivers' preferences. Porsche drivers have 24 buttons and switches in direct access - plus six paddles at the rear side of the wheel. The device is a proof of the quadrature of the circle in that this wheel is not circular but rather a flat rectangle. In the centre of the wheel. a large screen displays various types of information such as speed, gear currently engaged and charging status of the lithium ion battery - because the WEC racing car has a hybrid drive whit an electric motor that drives the front axle and thus complements the two-litre four-cylinder internal combustion engine which drives the rear wheels. The battery status informs the driver about the amount electrical energy that can be called up to boost the overall power, for instance during passing manoeuvres.
The thumb wheel in the right grip handle dims the display brightness - essential during the night. The identical wheel in the left handle sets the volume of the pit radio while the thumb wheel at the top of the left grip selects the information displayed on the screen, and its pendant at the right side varies the interval timing for the windscreen wiper.
Fig. 1: The steering wheel of Porsche's WEC LE Mans Prototype car. For full resolution click here .
The buttons and switches on the steering wheel were carefully positioned to facilitate reliable operation at racing pace and ensuring the short reaction times. The most frequently used buttons are positioned along the top outside edge, so they are easily reached with the thumb. The blue button at the top right which is almost always in use, is the headlamp flasher, used to warn slower vehicles in the WEC field before they are lapped. When pushed once, the headlamps flash three times. In daylight, the drivers keep their thumb on it almost permanently,