The present thesis is part of a broader project which main objectives is the engineering of a newly conceived mono-fuel hydrogen internal combustion engine (ICE), which will allow a reduction of emissions and cost with respect to the nowadays fossil fueled based powertrains. The range of applications is wide and space from automotive to offroad to power generation. In the present study, the primary aim is to analyze the environmental footprint of a hydrogen fueled engine achieved by retrofitting an existing diesel-powered ICE with a purposely made conversion procedure. One significant advantage of this retrofit technique is its ability to exploit existing infrastructure, allowing for a smoother and faster shift to greener energy sources.