Cars: What is direct fuel injection?

(NC) — Manufacturers are using innovative technologies such as direct fuel injection in an effort to offer consumers more fuel-efficient vehicles.

Direct fuel injection systems are better on fuel, lower emissions and increase power by injecting fuel directly into the cylinder at a high pressure.

Direct injection systems allow for better control of the fuel-air mixture and can reduce fuel consumption by one to three percent. Since reducing fuel consumption has a direct effect on reducing CO2 emissions, reductions of the overall fuel consumption of personal vehicles are clearly better for the environment.

How do direct fuel injection systems work?

Vehicles are equipped with engine sensors that provide feedback about fuel burn quality, engine pressure and temperature to the vehicle's electronic control unit (ECU). This information allows the ECU to constantly optimize the amount of injected fuel and the injection timing in response to changing driving conditions.

Direct fuel injection systems must be designed to withstand the harsh environment of combustion and to operate at high fuel pressures, increasing their cost and complexity compared to traditional injection systems. Despite this added cost, direct fuel injection gives more precise control over the quantity of fuel injected into the cylinder, the timing of the injection, and the spray pattern. This increased control leads to a higher quality of combustion and greater fuel efficiency than the conventional injection systems.

Since direct fuel injection increases the combustion efficiency and results in greater power, the technology allows for a smaller capacity engine. All of this can reduce fuel consumption and emissions by about one to three percent, compared to conventional technology. Over 10 years, this reduction corresponds to fuel savings ranging from $150 to $1,050 and CO2 reductions ranging from about 300 kg to 2,400 kg.

There is more information available about direct fuel injection at