DME is the simplest ether primarily produced directly from syn gas or indirectly by dehydration of methanol. Due to the chemical structure of DME, the possibility of forming carbonaceous PM and NOx emissions during combustion is limited [15]. DME combustion does not produce soot and is considered a clean fuel. Unlike methanol, DME is a gas at ambient temperature and pressure, so it is stored under pressure as a liquid similar to liquefied petroleum gas (LPG) and can use the same existing infrastructure as LPG [16]. The most challenging aspects of a DME en- gine relate to its physical properties and not its combustion characteristics. A DME fuel storage tank must be twice the size of a conventional diesel fuel tank due to the lower energy density of DME compared with diesel fuel, in order to achieve an equivalent driving range to CIDI (Compression-Ignition Direct-Injection) diesel. Modifications to pumps and fuel injectors are needed due to the 20-fold lower viscosity of DME compared with diesel [17].