Pass-By Noise (PBN) generated by road vehicles is one of the most relevant environmental issues, in particular for urban areas. The reduction of the PBN relies on experimental work considered in a late stage of the vehicle development process, as today no reliable prediction tool is available. Thus, noise reduction procedures are extremely time/cost intensive and don't lead to optimised low noise vehicle concepts. To contribute for the solution, hybrid engineering tools (simulation & test) for the PBN prediction are proposed. A novel methodology and prediction system will be developed in order to assess possibilities for future low noise vehicles. To demonstrate the validity of the developed prediction methodology, a 3 dBA target for noise reduction has been defined for two demonstrator vehicles modifying the power train and exhaust/intake systems.