A method of and system for reducing engine environmental atmospheric pollution emissions from a vehicle having a combustion engine utilizing hydrocarbon fuel for at least one of propulsion and auxiliary electrical power is disclosed. The method basically includes providing an unprocessed bulk fuel storage container and a clean processed fuel tank on the vehicle, supplying the engine for propulsion with fuel from the unprocessed fuel storage container when the vehicle is beyond a predetermined distance from an area having environmental restrictions passing a portion of unprocessed fuel through a desulphurization process to fill a clean fuel storage container while the vehicle is in motion and supplying the combustion engine for one of propulsion and auxiliary electrical power from clean fuel in the processed fuel storage container when the vehicle is within an area having environmental restrictions.