| The increase in number of vehicles has contributed to higher fuel consumption. To reduce the consumption of fuel, then one of method is the use of water methanol - air injection. This method is the inclusion of a mixture of water and methanol and air into the combustion chamber. This thesis study conducted experiments where the objective is to determine the effect of the use of water methanol - air injection to engine performance in the Otto engine by comparing the torque, power, specific fuel consumption and exhaust emissions. The results showed an increase in maximum torque of 12.67% on the addition of pure water, 15.13% by mixing 25% methanol, and 15.51% by mixing 50% methanol. An increase in maximum power of 13.4% on the addition of pure water, 14.1% by mixing 25% methanol and 17.1% by mixing 50% methanol. As well as a decline in specific fuel consumption which for a mixture of 50% methanol decreased the most. CO levels tended to decrease but increased HC levels. |