This study is an experimental investigation into the effect of methanol addition to gasoline on the performance of spark ignition engines. The performance tests were carried out, at wide open throttle and variable speed conditions, over the range of 1000 to 2500 rpm, using various blends of methanol-gasoline fuel. It was found that methanol has a significant effect on the performance of the gasoline engine. The best engine performance (within the range studied) for maximum power output, and minimum brake specific fuel cosumption, occurs when a mixture of 15 volume percent methanol and 85% gasoline blend is used. The addition of methanol to gasoline increases the octane number, thus engines fueled with methanol-gasoline blend can operate at higher compression ratios.