Abstract
The low lubricity and viscosity of DME as a fuel affects the wear and leak problems at the injector system. A HFRR is the one of the method to estimates the lubricity. However there is no data regarding the nozzle tip. Then an newly developed test rig is used to evaluate the injector wear. As results, the polymer type additive around 200ppm shows the good wear resistance. In the engine examination, the wear depth has increased by about 80% compared with that of test rig. This wear depth doesn't influence the injection timing, therefore, there is no change the amount of the NOx emission. Furthermore, the polymer type additive decomposes at the temperature at 350C.
