The compression ratio is one of the benchmarks in determining the appropriate fuel RON for motorized vehicles. The use of RON that is not following the manufacturer’s specifications can undoubtedly hurt engine performance. The purpose of this study was to analyze the effect of premium, pertalite, Pertamax, and Pertamax turbo fuels on engine performance. This research is experimental research where the object of study used is the Honda Supra X 100cc. The research instruments and equipment used included a dynamometer chassis and a blower as a cooling fan. The engine performance testing method is carried out according to the SAE J1349 standard. Meanwhile, the data analysis technique used descriptive methods. From the results of data analysis obtained from the study, it is concluded that the RON 88 is suitable for 3000-4000 rpm, while RON 90.92.95 is suitable for 4500-7000 rpm, in addition to motors that have a compression ratio of 8:1 they can use RON 90.92.95 without modification to the engine.