For many years in the Department of Automobiles and Internal Combustion Engines in Technical University of Radom there are carried out investigations on dual-fuel compression ignition engine in which the ignition is initiated by a pilot diesel oil dose and the applied main fuels have properties similar to those applied in spark ignition engines. The tested fuels were methanol, ethanol, LPG and natural gas. Analysis of the obtained results allowed to make some generalizations and to determine advantages as well as problems which should be solved for higher efficiency, power and durability. The paper will present information on efficiency, power, toxic exhaust emission and chosen parameters of combustion process of a dual-fuel compression ignition engine as well as on a difficult to control – knock combustion which may result in lower engine durability and piston crank mechanism failure.