Every average sized harbour use a lot of cranes, trucks and other vehicles for loading and reloading incoming and out going ships. These vehicles are usually run by different diesel distillates, which emit pollution to the atmosphere. According to legal permissions based upon both European and national legalisations, the emission factors have to be reported in to the municipal environmental protection authorities. This present study presents methods in calculating gas exhaust emissions from these vehicles which effect the surrounding environment both to the nearby water and to the regional atmosphere. The calculation model is based upon fuel consumption and future possibilities to decrease this consumption and trade out some of the worst polluting distillates to other more ecological fuel systems.