The invention relates to a self-igniting internal combustion engine (10) with ether fumigation of the combustion air for vehicles, wherein to provide for ether fumigation, a feed means (1, 2, 3) is provided for an alkanol fuel in the flow direction, an exhaust gas heat exchanger (4) is provided for cooling a portion of the exhaust gas arising from the firing of the internal combustion engine (10) and for vaporizing the alkanol fuel fed while at the same time absorbing the thermal energy to be dissipated during cooling of the exhaust gas, and a catalyst (5) is provided for dehydrating the evaporated alkanol fuel to form ether, and wherein the feed means (1, 2, 3), the exhaust gas heat exchanger (4) and the catalyst (5) are connected to the combustion chamber of the internal combustion engine (10) and adapted in such a way that a portion of the fuel required to fire the internal combustion engine (10) can be fed to the combustion chamber of the internal combustion engine (10) by way of the ether fumigation of the combustion air while mixing in the exhaust gas cooled in the exhaust gas heat exchanger (4). The invention further relates to a method for ether fumigation of the combustion air in a self-igniting internal combustion engine for vehicles.