Dual spark plug solution

1. Early automotive dual spark plug solution
Many years ago, engineers from foreign car companies were wondering whether they could light the fire one more time to make the combustion more intense. If fuel can be "digested" better, then it can "eat" less and emit less fuel.
1978. Nissan's Z181.8L dual-spark plug four-cylinder engine is the originator of the currently known dual-spark plug automobile gasoline engine.
This technology of two spark plugs per cylinder is called NAPS-Z, which comes from technical support from Hitachi. In layman's terms, it is electronically controlled dual ignition fuel injection. It is used in Nissan Z series engines. Later, the dual spark plug method was used on Nissan's CA series engines, called NAPS-X, replacing NAPS-Z.
Features of NAPS-Z are:
The combustion efficiency is excellent, so the fuel economy and drivability are good.
The exhaust gas is reduced, CO, HC, and NOX are reduced, and the fuel is burned stably.
Solved the problem of combustion noise caused by rapid combustion.
The technology achieved with the streamlined exhaust system was well received and won awards.
The engine's ease of starting is improved.
Structurally simple and easy to implement.