Common-Rail technology optimises fuel injection to match driving conditions, achieving efficient combustion at all times to establish a balance between high output and fuel economy.
In contrast to conventional diesel systems, generation of injection pressure in the Common-Rail system is separate from the injection itself.
Common rail engines:
Diesel is fed from the priming pump into the high pressure pump which then pressurises the fuel to 2,000 bar (29,008psi). The fuel accumulates in the common rail via the pressure limiter valve and is then injected directly into the combustion chamber at this high pressure.
Conventional injection systems differ from the common rail system in that they work by injecting the fuel at a much lower pressure of around 120 bar (1,740psi).
The advantage of high pressure injection is that it atomises the fuel into a fine mist and distributes it evenly throughout the combustion chamber allowing for a better air/fuel mix.
The exact quantity and timing of the injection is calculated by the Powertrain Control Module (PCM) ensuring optimal combustion matching the current driving conditions.