Alcohols are examined as supplemental carbureted fuels for highspeed turbocharged diesels as typified by the White Motor/Waukesha F310 DBLT (6 cylinder, 310 cu. in.). Most of the work was with methanol; ethanol and isopropanol were compared at a few points. Fumigation (dual-fueling) with alcohol significantly reduced smoke and intake manifold temperature. These effects were largest at high load. Efficiency and HC emissions were essentially unchanged. Cylinder pressures and rise rates were examined for possible adverse effects on engine structure. The range of speed and load favorable to alcohol dual-fueling are such that, should alcohols become economically competitive as fuels, a practical duel-fuel system could be applied to existing diesel engines.