The ultimate goal of automotive manufacturers is the development of more powerful, economical and environmentally friend internal combustion engines. Also of note is the importance of noise reduction by increasing the fuel injection pressure to unsatisfactory levels. Obviously, higher injection pressures require materials of higher strength and lower production tolerances. However, one of the main issues regarding the use of these high-pressure fuel systems is their dependency on fuel quality. Therefore, concurrent efforts to improve diesel fuel quality are supremely important. In this study, we discuss the earliest engine problems commonly encountered in new generation diesel engines and their economical consequences for vehicle owners and the Turkish automotive market. We found that most of the problems in connection with the Common Rail (CR) systems emerged from inadequate fuel quality. In Turkey did not proceed at the same rate as the increase in diesel vehicle sales, because the improvement of fuel quality. Other reasons for the problems include faulty operation, lack of necessary knowledge particular to CR technology and late response to a problem by the drivers.