Hi-tech on four wheels

Smaller than fingernail and weighting just a few grams, microprocessors at first glance may seem rather insignificant objects. But appearances can be deceptive.

Integrated on these shiny metallic silicon slices are several hundred thousand microscopically small transistors which, when their powers are combined, can achieve remarkable feats. Protected inside a plastic or ceramic casing, microchips constitute the core of a computer, maintaining and monitoring BMW's various on-board electronic systems - from air conditioning to anti- lock braking, fuel injection or traction control. One thing is certain: without microelectronics, the driving comfort and high safety standards of a modern BMW would be entirely inconceivable.

BMW technicians installed their first microprocessor as far back as 1979. It controlled the newly-developed DME digital engine management system (an industry first). In the meantime, silicon chips are a well-established constituent of every new BMW. Even the basic version of the 3 Series has no fewer than ten microprocessors on board. A 7 Series model, depending on equipment levels, can contain up to sixty of these miniature computers.

They work at astonishing speeds. The core of central engine management in the current M3 executes nearly twenty million instructions per second (20 MIPS).

Microprocessors also have a reputation for being extremely reliable. They are designed for a lifespan of at least 150,000 active hours. A car by comparison, is expected to survive 4,000 hours of use. Long before a chip has to retire due to old age, the car in which it has served will probably have ascended to the great car park in the sky.

From BMW Magazine