Nissan today announced the development of a Dual Injector system designed to improve fuel efficiency in small-displacement petrol engines. The new fuel delivery system, the first of its kind in the world (for mass produced cars), uses an injector for each port rather than one per cylinder – speeding up fuel vaporization, reducing the amount of unburned fuel and reducing hydrocarbon emissions.

While most current petrol engines utilize one injector per cylinder (sending fuel to two intake ports), the new Nissan Dual Injector system doubles the number of injectors per cylinder. This reduces the diameter of the fuel droplets by about 60%, resulting in smoother, more stable combustion.

The system also adds continuous valve timing control on the exhaust side to conventional intake-side control, improving heat efficiency, reducing pumping losses and raising fuel efficiency by up to 4% in sync with the dual injectors.

While similar in theory to direct-injection systems, which also inject fuel directly into cylinders, such direct injection systems are difficult to use on small-displacement engines because they require a high-pressure pump that complicates system design, making component layout less cost-efficient. In contrast, the Nissan Dual Injector system is lighter and structurally simpler because it sends fuel at normal pressures, reducing cost by about 60% compared to direct-injection engines of similar displacement. The system also requires half the amount of rare metals in the catalytic converter compared with a standard engine, helping to further reduce costs.

The first production application will appear early next year but so far no actual models have been confirmed.