Effects of intake preheat engine on performance and emissions of a compression ignition engine running on biodiesel (85%)-alcohol (15%) fuels were investigated and compared to baseline results of standard diesel and neat biodiesel. Emissions were compared at two elevated intake air temperature and results indicate that high heat of vaporization of alcohol fuels affect emissions significantly. Intake air preheat was proved to be one of the effective solutions to reduce CO and HC emissions. Reduction of alcohol concentration in biodiesel-alcohol blends also showed similar effects to preheating intake air temperature. (C) 2011 Elsevier Ltd. All rights reserved.