Carbon-footprint from transport and power generation can significantly be improved when carbon free or reduced carbon energy carries are utilised that are compatible with the current technology of the internal combustion (IC) engines. The current study focuses on the reduction of diesel engine CO2 emissions by improving ammonia and hydrogen combustion through the incorporation of alternative fuel, diethyl glycol diethyl ether (DGE) as an oxygenated fuel blend and combustion enhancer. The aim of the work is to study the potential synergies between DGE and two carbon free energy vectors H-2 and NH3 in reducing the environmental effects and contribute in decarbonising internal combustion engines. DGE's ignition properties (i.e. high cetane number) improved the H-2 and NH3 combustion efficiencies via counteracting their high auto-ignition resistances, and also contributing in lowering the unburnt H-2 and NH3 emissions to the atmosphere. This led in the reduction of CO2 by up 50% when 60-70% of diesel fuel is replaced with DGE, H-2 and NH3. Synergetic effects were also found between DGE and the gaseous fuels (i.e. hydrogen and ammonia) simultaneously decreasing the levels of PM, NOx, HC and CO emitted to the atmosphere; thus mitigating the health and environmental hazards associated to diesel engines. (C) 2016 Elsevier Ltd. All rights reserved.