Traditional coils (oil filled/wet coils/can type). The oil-filled ignition coil is also called open magnetic circuit type ignition coils. In conventional ignition system, oil filled ignition coil was used widely, and also applied in the electronic ignition system later which structure is the same as the ignition coil used in the conventional ignition system. Ignition coil has two coils of wire, the primary coil and the secondary coil. Primary coil with thicker enameled wire, usually around 0.5-1 mm enameled wire around 200-500 turns.

Ever since the advent of modern vehicles governed by engine management systems. Ignition coils have undergone a dramatic change. The old oil filled cylindrical (wet) coils have been replaced completely by dry coils; these come in all shapes, styles, sizes and functions. With the development of technology, the type of ignition also is improved.

Distributor less ignition coil (single spark ignition)
Single spark ignition coils can be used in engines with both even and uneven numbers of cylinders. However, the system must be synchronized via a camshaft sensor. Single spark ignition coils generate one ignition spark per power stroke. Ignition voltage losses are the lowest of all ignition systems due to the compact design of the single spark coil / spark plug unit and the absence of ignition cables. Single spark coils enable the largest possible range of ignition angle adjustment. The single ignition coil system supports monitoring of misfiring in the ignition system on both the primary and secondary side. Any problems that occur can be reduced in the control unit.