Virtual NVH Engineering is going to be reviewed in this paper for the development of FIE (fuel injection equipment) components. Some examples based on high pressure pumps and SCR air cooling injectors will illustrate the explanation.The use of a 3D FEM vibro-acoustic model is essential to support virtual NVH Engineering. Therefore, a review of techniques to study components is done first. Model correlation is also an important topic which will be discussed and which makes any NVH engineer confident in using a model instead of real HW. It is quite challenging to establish these models, as they must mimic the entire physical phenomenon of real structure borne hardware sound in the whole audible frequency range. Limitations of models are also identified and allow answering one true question: Should we stay considering only each component separately or as an assembly of parts of a larger system in the development process?Once a model of the studied component or system is established, some comparisons of variants can be initiated in the virtual domain. Standard spectrum analysis can be completed with psychoacoustic criterion to better judge the quality of the predicted sound by simulation and to decide for the best design solution.