Biodiesel synthesis from rubber seed oil using superheated methanol and 2-propanol was comparatively evaluated in this study. For conversion, the alcohol was pre-heated far beyond its boiling point and then allowed to flow into heated oil in the reactor, where spontaneous conversion takes place, before being collected with the formed product after cooling. Batch studies were used to estimate the suitable range of parametric values for central composite design optimization. Product separation requires only distillation for alcohol removal, while formed glycerol is recovered from the unreacted oil via centrifugation. Methanol converts the oil faster than 2-propanol but propyl esters have higher thermal stability. Optimal fuel yields of 98.59% and 96.92% were obtained using initial oil mass of 400 g at preheat temperatures of 130 °C and 140 °C when reaction temperatures were 240 °C and 260 °C for 7 min and 8 min respectively with methanol and 2-propanol. Fuel characterization shows its suitability for use as biodiesel according to standards set for commercial biodiesel. Boasting a high rate of conversion and simple operation along with easy product separation, the superheated conversion approach described here can therefore be scaled up for commercial application and even made continuous with some appropriate modifications.