A technology developed at the University of Wisconsin-Madison called Reactivity Controlled Compression Ignition (RCCI) uses two injectors, per cylinder, to mix low-reaction fuel (gasoline) with high-reaction (diesel) fuel ignition (ICO). This technique allowed greater control of the combustion process, reduction of fuel consumption and exhaust gases harmful to the environment. In this work was used a single-cylinder compression ignition (IC) engine, modified to operate with RCCI technology, injecting diesel and ethanol directly into the combustion chamber. The objective was to achieve the highest rate of substitution of diesel by ethanol, using double and triple fuel injection strategies. Test results show that modified engine efficiency improved when the dual fuel injection strategy (ethanol at -170 degrees PMS and diesel at -8 degrees PMS) was used, but high pressure points appeared inside the cylinder that could damage the engine. Using another dual fuel injection strategy (diesel at -8 degrees PMS and ethanol at + 4 degrees PMS) no pressure peaks were detected inside the cylinder, but a decrease in efficiency occurred. The most promising results were obtained using the triple fuel injection strategy (ethanol at -170 degrees PMS, diesel at -8 degrees PMS and ethanol at + 4 degrees PMS): efficiency increased and the highest diesel substitution rate by ethanol was achieve (74,6 percent).