Several big players in the global car and truck market are rekindling an interest in dimethyl ether, or DME, as an alternative fuel, largely because it's relatively cheap, requires very low injection pressures, and produces little pollution.

“Although DME's energy density is lower than diesel, the overall engine thermal efficiency is the same or higher,” explained Jim McCandless, CEO of Alternative Fuel Technologies. “DME also costs less than diesel on an equal energy basis; 1.8 gals. of DME will cost less than 1 gal. of diesel, assuming a $70 per barrel or higher oil price.”

McCandless said the fuel's sootless nature permits the use of very high exhaust gas recirculation rates to lower oxides of nitrogen emissions without having to use after-treatment devices.