Nissan dual fuel injection on 1.6L Micra engine HR16DE

[MetroMPG]

Above: Dual fuel injection system configuration.
Information source: http://www.nissan-global.com/EN/TECH..._injector.html

To improve combustion stability and efficiency, one well known approach is reducing fuel droplet diameter.

The Dual Injector system uses 2 narrower injectors per cylinder mounted closer to each intake valve, so the injectors can have smaller nozzle holes, wider spray cone angles, and shorter spray cone lengths.

With this approach the dual injector system realizes smaller fuel droplet size and results in smoother, more stable combustion.



Shown above, a conventional single injector must be placed further from the intake valves, and its narrower and longer spray cone has a larger average fuel droplet size.

Benefits:

With dual injection in combination with Continuously Variable valve Timing Control (CVTC), fuel efficiency is increased by up to 4% compared with Nissan gasoline-powered engines in the same class.

This combined approach also results in less unburnt fuel in the exhaust, so half the amount of rare metal is required in the catalytic converter.

See also: HR16DE Micra engine: 1.6-litre 4-cylinder info (specs, specifications)