The aim of the present study is to investigate the effect of Intake air temperature on the performance of gasoline engines. Various factors are taken that affect the performance of four-stroke gasoline engines. Changes in air intake temperature have a significant impact on the performance of a petrol engine. Consequently, an increase or decrease in the global ambient temperature will impact the performance and air quality of gasoline engines in particular. therefore, this investigation will discover the hot value of intake air temperatures that effects engine performance.  This study tested two Kurdistan-Iraq gasoline kinds at different intake temperatures (25C^o, 35C^o, 45C^o, and 50C^o). Experiments utilized a four-stroke spark ignition _engine that operated at various rates of speeds (1300, 1500, 1800, 2000, 2300 and 2500 revolutions per minute) under a half load with a 50% throttle opening. The experimental outcomes were compared with Ricardo Wave software simulations. The Ricardo Wave's theoretical outcomes were in good agreement with the experiment data it showed a near 5% to 10% variance between simulation and practical data. Additionally, utilizing fuels having higher RON increases brake power owing to gasoline's greater hydrogen content and the engine's high octane fuel requirement. Also, lower inlet air temperatures would be denser (more oxygen) and offer a larger mass flow during each piston cycle. Hence, due to those factors, brake power was enhanced by reducing intake temp and raising RON. Generally, the experiment results demonstrated that utilizing higher octane number gasoline under lower intake temperature improved engine performance which demonstrates higher power, torque, and efficiency with lower bsfc compared to utilizing higher intake temperature and lower octane gasoline.