Over the last few years, Renault VI has gained an important knowledge in low emissions combustion optimization using the high injection pressure Common Rail system. A completely new six cylinder in-line DCI 11 engine has been designed with this full electronic injection system for EURO3 truck applications.The engine performance has been optimized to reach low fuel consumption and low emissions, while keeping customer utilization in mind. After a short view on the general features of the new engine, the highly flexible injection system is presented as well as its potential to control fuel injection timing, fuel quantity and pressure with multiple injections, independently of engine speed and load. The development process is described, covering the swirl design with two inlet ports per cylinder, the injector and combustion bowl geometry match and the injection data optimization. With the advantages of the high flexibility of the injection system, it became mandatory to use modern tools such as three dimensional computations of injection and combustion, and statistical experimental design techniques with single cylinder tests, before the final development phase of combustion with multiple-cylinder.Some auxiliary functions, such as the low pressure fuel circuit, the injection fuel pressure control, and the fuel filtration, required developments to take full advantage of the Common Rail system under steady-state and transient conditions.This high performance engine introduces a new generation ready to meet future regulations, and is designed to further improve customer satisfaction.