Abstract: An oxygenate additive analyzer is provided which detects and determines the presence of oxygen enhancing additives in gasoline or other fuels. The oxygenate additive analyzer includes a portable electronic controller with a fuel cell connected to the controller by a ribbon cable. In operation, a sample of the fuel to be tested is placed in the fuel cell and electrical control signals are transmitted between the controller and the fuel cell. The analyzer measures the direct current conductivity, resonant frequency, and temperature, and such data is analyzed on the unique software system in the microprocessor of the controller. Upon the completion of the fuel analysis, the controller displays the percentage, if any, of added oxygen by weight, lists probable oxygenates as a percentage of volume, and shows the temperature of the fuel sample. The analyzer is a portable unit with a battery power supply.