The way in which fuel is injected into the cylinders of diesel vehicles determines their torque, fuel consumption, emissions and noise level. Two factors are key: the fuel pressure as it enters the cylinder, and the shape and number of the injections.

     A common rail injection system separates these two functions (generating pressure and injecting) by first storing fuel under high pressure in a central accumulator rail and then delivering it to the individual electronically-controlled injection valves (injectors). This ensures that incredibly high injection pressures (in some cases over 25,000 pounds per square inch) are available at all times.

     Common Rail Injection and Advanced Clean Diesel Systems All internal combustion engines need two key ingredients to operate: air and fuel. The precise delivery of these ingredients is what makes clean and powerful combustion possible. Just as turbochargers help deliver copious amounts of air to help diesels operate cleanly, efficiently and powerfully, the parallel revolution in fuel delivery has ushered in the renaissance of diesels in Europe. High fuel pressure produces a fine mist of fuel that burns better and cleaner in the combustion chamber. Not only that, but for each combustion cycle, the common rail allows up to five injections per cycle. The driver benefits as lower fuel consumption (improved mileage), better engine performance and less noise compared with older diesels.