A fuel which is ethanol-based and which has the form of a solution includes from 62-94% by weight of ethanol; from 2-8% by weight of water; from 2-30% by weight of an ignition improving agent comprised of a water-soluble polyalkylene glycol compound containing 6-50 alkyleneoxy units with 2-4 carbon atoms and having a molecular weight of less than 2500. Such fuel is useful for fueling diesel engines and has excellent combustibility while emitting a low content of organic hydrocarbons. At the same time, the polyalkylene glycol ignition improving agent is odorless, non-toxic, stable in storage, and does not emit nitrogen oxides when combusted.