Pengaruh Pemanfaatan Gasoline 80% dengan Variasi Konsentrasi Ethanol dan Methanol Terhadap Specific Fuel Consumption dan Coefficient of Variation pada Engine Test Bed 125 cc dan Road Test Engine 1800 cc = Effect of 80% Gasoline Utilization with Variations in Ethanol and Methanol Concentrations on Specific Fuel Consumption and Coefficient of Variation on 125 cc Engine Test Bed and 1800 cc Road Test Engine