Leave it to the automotive experts in Japan to come up with yet another way to drive down fuel consumption.
Nissan has developed a dual injector system which uses port fuel injection (PFI) to improve the fuel efficiency of small displacement petrol engines. Whereas most current power fuel injected engines use one injector per cylinder, this system uses an injector for each intake port.
This novel fuel delivering system is the first for a series production passenger car according to Nissan, and it reduces the diameter of the fuel droplets by around 60 per cent. This in turn speeds up vaporisation, which reduces the amount of unburned fuel and hydrocarbon emissions.
The system uses continuous valve timing control on the exhaust side to conventional intake-side control. This boosts heat efficiency while reducing pump losses and increasing fuel efficiency by as much as four per cent. The system is lighter than direct-injection systems which inject fuel directly into cylinders and structurally simpler as it furnishes fuel at normal pressures. It also uses around half the amount of rare metals in the catalyser while maintaining the efficiency of a normal catalytic conversion system.
According to Shuichi Nishimura, the corporate vice president of Nissan Powertrain engineering division, this is an important development to further improve the fuel efficiency of petrol engines and will help to reduce emissions and conserve rare metals.
