NISSAN HAS ANNOUNCED details of its all-new Dual Injector technology designed to improve fuel efficiency in small-displacement petrol engines.
The first of its kind for mass-production in vehicle engines, the new fuel delivery system speeds up fuel vaporisation by using an injector for each port rather than one per cylinder. The result is a reduction in unburned fuel and hydrocarbon emissions.
Unlike direct injection systems which require a high-pressure fuel pump (complicating system design in small-capacity engines and increasing cost), Nissan's "structurally simpler" Dual Injection technology delivers fuel at normal pressures, "reducing cost by about 60 percent compared to direct-injection engines of similar displacement", Nissan claims.
Where most petrol engines feature one injector per cylinder, Nissan's Dual Injector system uses two (one for each intake valve port), resulting in smoother, more stable combustion.
The Dual Injection system also features continuous valve timing control on the exhaust side and conventional intake cam control, offering improved heat efficiency, reduced pumping losses and raising fuel efficiency by up to four percent when used in sync with the dual injectors.
?We consider it important to further improve the fuel efficiency of gasoline engines as demand for gasoline and other internal-combustion systems continues to increase around the world,? said Shuichi Nishimura, Corporate Vice President, Nissan Powertrain Engineering Division.
?By widely applying the Dual Injector system on small-displacement engines, we hope to help reduce CO2 emissions and conserve rare metals.?
Nissan says that its system is unique in that, unlike direct injection systems which require a high-pressure fuel pump (thus complicating the design of small-capacity engines), the Dual Injection technology only needs fuel at normal pressures.
Thanks to its lighter and structurally simpler design, Nissan's Dual Injection system can also be produced at a lower cost - around 60 percent cheaper than an equivalent Direct Injection system - and uses half the amount of precious metals (such as platinum) in the catalytic converter compared to a standard engine.
The first production use of the Dual Injection system is scheduled for 2010, but Nissan has yet to confirm which models will see the technology first.