It is presumed that the world’s present oil resources may be wiped out in about in about 42 years. Moreover the estimated time of the world future oil resources depend on the price demand. At the same time possibility of supply of crude oil by several times at the present price might be impossible. Therefore a new fuel should be linked to the oil resources.

Next there are problems of urban air quality standard and a global environment. The exhaust emissions from gasoline engines are becoming very clean with aid of advanced fuel formulation, intake air quantity, in-cylinder combustion control and exhaust gas after treatment technology. But the exhaust emissions of heavy-duty diesel vehicles play a massive role in environmental pollution by emitting NOx and soot (PM). The PM emissions can be reduced through engine modification such as the use of very high injection pressure etc. NOx may be reduced to some extent by retarding the injection timing or by employing exhaust gas recirculation system. However suitable catalysts are yet to be established.

DME (Dimethyl ether) is a new alternative fuel that can be used to solve the environmental pollution problems along with providing many other utilities. Several experiments have been carried out on the fuel and satisfactory results have been obtained. Lower emissions are produced and other advantages include thermal efficiency and low engine noise with DME compared to the diesel engine operating with conventional diesel fuel. The cost of DME is only 1100RMB/tonne, which is much lower than diesel on an equal energy basis. DME is an excellent and environmental friendly alternative fuel for diesel.