The phase behavior and clouding phenomena of some microemulsions (ME) containing the mixtures of diesel and kerosene at various proportions (oil phase: O), non-ionic Tween-80 surfactant (S), n-butanol or isobutanol cosurfactant (C), and water or brine as the aqueous phase (W) have been discussed. Some of the microemulsions have been characterized through the study of their electrical conductivity and temperature-induced three phase separation methods to recognize their o/w, w/o and bicontinuous zones. The phase transition temperature and the surfactant efficiency for some of the systems have been studied to map the percent oil solubilization in the water phase. The densities of the microemulsions have been determined and the fuel compatibility and possible fuel applications have been predicted from their flame brightness and the amount of soot formed during their inflammation. A remarkable impact of the structure of alkyl cleft of n-butanol and isobutanol cosurfactants on the properties of the microemulsions has been observed. (C) 2015 Elsevier Ltd. All rights reserved.