This study proposed a dual fuel operation of a mix of gasoline and producer gas from coal gasification on the spark ignition engine. The experiment was carried out on a constant load with variations in speed for single fuel operation of gasoline and dual fuel operation of a mix of gasoline and producer gas to see the influence on speed, torque, power, and braking (effective pressure). The power produced was compared to power produced by the single fuel of producer gas that has been reported in the literature. The result shows an increase of speed would increase torque, power, and braking (effective pressure) for single fuel operation of gasoline and dual fuel operation of a mix of gasoline and producer gas. The power operation of dual fuel of a mix of and gasoline and producer gas will decrease by about 10.9% compared to operation of single fuel of gasoline, and the power operation of the single fuel of producer gas will decrease by about 20% compared to the operation of the single fuel of gasoline. The maximum shaft power produced by dual fuel operation is 1.49 kW at a load of 5 kg and a speed of about 3,500 rpm.