Abstract: A method for controlling an internal combustion engine is disclosed in which a first fuel, hydrogen, is supplied under a first set of engine operating conditions and a second fuel, such as: gasoline, gasoline mixed with alcohol, or gaseous hydrocarbons, are supplied under a second set of engine operating conditions. The first set of engine operating condition is below a threshold BMEP and the second operating condition is above the threshold BMEP. Alternatively, the first and second set of operating condition is based on temperature of a three-way catalyst coupled to the engine. When its temperature is greater than its light-off temperature, the second fuel is used.

Abstract: The invention relates to a diesel engine in which a separate camshaft (12) for independently controlling the closing of the inlet valves (IVC) is provided, which camshaft is coupled to phase-shifting mechanism (14). By delaying the closing of the inlet valves independent from other valve events, it is possible to vary the effective compression ratio of the diesel engine. The extent of the delay of the closing of the inlet valves is, preferably, adjusted based on the engine speed, the engine torque and/or the charging pressure of a turbocharger.