The continuous development of an ignition system has advanced over the years – and with it, the ignition coils used by car manufacturers. In general, ignition coil technology can be split into two fundamental operating principles: ‘single spark technology' and ‘dual spark technology'. With single spark technology, there is an individual coil for each spark plug supplied. With dual spark technology, two cylinders are always actuated simultaneously by one coil. Due to the high demands placed on ignition coils, the design and the materials used must be resistant to heat and moisture in the engine bay and function reliably. Oil and petrol vapours mustn't be able to harm the housing, as damage to the housing would impair the function.