In order to reduce harmful emissions in the exhaust of internal combustion engines, there is a need to choose an alternative fuel. Among other substitute fuels for fuels based on petroleum, methanol is considered one of the most favorable for internal combustion engines. This bachelor thesis analyzes the changes in the operation characteristics of the conventional Otto engine for the case when gasoline fuel would be changed to methanol. The adventage of methanol over gasoline is a higher octane number and higher specific heat of vaporization, as compared to gasoline, which makes it suitable for applications in engines with a high compression ratio and large output power. By using the AVL BoostTM program package, a simulation of a simplified Otto engine was made, adjusted to give the torque values declared by the manufacturer. While converting fuel to methanol, two simulation configurations were made. The first configuration was made by replacing gasoline with methanol without changing the operating parameters, while in the second configuration, the operating parameters of the engine have been changed to achieve the highest efficiency. The performance characteristics obtained by switching to methanol are shown in diagrams. Based on the completed simulation calibrations, comparative topographic diagrams were made for the performance characteristics of the gasoline engine and the engine with a change of fuel to methanol, for which the best possible engine performance was achieved.