The collision and burning characteristics of freely moving droplets, individually generated by the merging of colliding high-carbon-number alkanes with low-carbon-number alcohols, and hexadecane with methanol+benzene mixture droplets, were investigated. It was found that the high-C alkanes/methanol and ethanol droplets were in an adhesive, unmixed manner, and that /1- or /iso-propanol droplets were in a mixing mode. By adding a substantial quantity of benzene, the adhesively merged hexadecane/methanol+benzene droplet could change to a mixing one. Strong explosion occurred for high-C alkanes/methanol and /methanol+benzene droplets, while a relatively weak explosion was observed for high-C alkanes/ethanol, with lower contents of alcohol, leading to faster global burning rates. The presence of alcohol vapor made the flame colors more bluish, indicating the soot reduction in alkane flame. The potential of separate injection of oil and alcohol in an opposed-jet arrangement to improve burning and reduce smoking in direct-injection engines is then suggested.