Methanol-gasoline blends have been under consideration for use as transportation fuels to help extend the current fuel supply. The use of these blends is limited, in part, because low temperatures and/or the presence of dissolved water can lead to phase separation. In this work, the effects 1 to 5 % w/v of a model twin-tailed surfactant, Aerosol OT (sulfosuccinic acid, bis[2-ethylhexyl] ester, [577-11-7]), on the phase separation temperature of a simulated gasoline-methanol fuel mixture doped with 0.1, 0.2, and 0.3% v/v dissolved water was studied. The Aerosol OT did lower the phase separation temperature substantially though not as much as straight chain surfactants examined in earlier work.