In this paper, we discuss the distribution of ethanol over fractions of alcohol-gasoline fuel. For the first time, quantitative data of ethanol distribution over fractions of ethanol-gasoline fuel have been obtained by the infrared (IR) spectroscopy method. Ethanol is found to nonuniformly distribute itself among gasoline fractions (thus, conclusions of earlier published works have been numerically confirmed). The form of ethanol distribution over fractions is found to be Gaussian-like. We found out that ethanol is concentrated in '' light '' ethanol-gasoline fractions and that it is almost completely absent in '' heavy '' ones (with a boiling point over 90 degrees C). The main part of ethanol (similar to 97% v/v) is found to form azeotropes-the reason for the fuel's high volatility.