Investigation of the Octane Rating and Autoignition Temperature of Methanol-Gasoline Blends

The octane rating and autoignition temperature of methanol-gasoline blends were measured. Large increases in autoignition temperature and ignition delay time were found for small percentages of added methanol. These increases correlated well with the increases in research octane rating throughout the range of blends. The evaporative cooling effect of the methanol was concluded to be the major mechanism suppressing detonation.