(US5632786-A)      A method of operating a spark ignition internal combustion engine having a cylinder, which comprises: withdrawing from a pressurized fuel tank a liq. phase mixt. consisting essentially of and propane; vaporizing the mixt. downstream of the fuel tank near the engine, based on the direction of mixt. flow, to produce a gaseous fuel within the range of about 10 to about 30 percent by wt. dimethyl ether and within the range of about 90 to about 70 percent by wt. of propane, based on the total wt.; passing air and the gaseous fuel into a cylinder of a spark ignition internal combustion engine; igniting the gaseous fuel by a spark; and operating the engine over a distance of about ten miles with the dimethyl ether-propane mixt. as fuel.    (EP793703-A1)      The spark ignition internal combustion engine is operated by vaporising a liquid mixt. to give a gaseous fuel comprising 10-30 wt.% dimethyl ether and 90-70 wt.% propane, passing air and the gaseous fuel to the engine cylinder and igniting the fuel with a spark.    Also claimed is a fuel compsn. comprising 10-70 wt.% dimethyl ether and 90-30 wt.% propane and its use in fuelling a spark ignition engine.    USE -   Used in the converted gasoline engine of a truck, bus or automobile.    ADVANTAGE -   On combustion the fuel gives less CO and unburned hydrocarbons than 100% propane. The mixt. has a lower vapour pressure than propane and is therefore relatively easy to liquefy and transport.    (JP10509210-W)      The spark ignition internal combustion engine is operated by vaporising a liquid mixt. to give a gaseous fuel comprising 10-30 wt.% dimethyl ether and 90-70 wt.% propane, passing air and the gaseous fuel to the engine cylinder and igniting the fuel with a spark.    Also claimed is a fuel compsn. comprising 10-70 wt.% dimethyl ether and 90-30 wt.% propane and its use in fuelling a spark ignition engine.    USE -   Used in the converted gasoline engine of a truck, bus or automobile.    ADVANTAGE -   On combustion the fuel gives less CO and unburned hydrocarbons than 100% propane. The mixt. has a lower vapour pressure than propane and is therefore relatively easy to liquefy and transport.    (CN1165535-A)      The spark ignition internal combustion engine is operated by vaporising a liquid mixt. to give a gaseous fuel comprising 10-30 wt.% dimethyl ether and 90-70 wt.% propane, passing air and the gaseous fuel to the engine cylinder and igniting the fuel with a spark.    Also claimed is a fuel compsn. comprising 10-70 wt.% dimethyl ether and 90-30 wt.% propane and its use in fuelling a spark ignition engine.    USE -   Used in the converted gasoline engine of a truck, bus or automobile.    ADVANTAGE -   On combustion the fuel gives less CO and unburned hydrocarbons than 100% propane. The mixt. has a lower vapour pressure than propane and is therefore relatively easy to liquefy and transport.