This report presents research carried out on an alcohol fueled bus engine. The engine used was a six cylinder 11 liter compression ignition turbo- charged engine with an inter cooler. The research program included studies of the impact on the emissions when changing different engine components and different settings of the engine. A study of the impact on the engine performance and emissions when using different fuel compositions was also carried out. During the course of the work, the engine was equipped with oxidation catalysts of two different types, one of which was more efficient than the other concerning the oxidation of unburnt fuel related components. One of the main purposes of the research was to improve the emission characteristics of the engine by an optimization of the engine and its setting. The exhaust emissions were thoroughly characterized with respect to both regulated and unregulated emissions