Internal combustion engine

A method of improving efficiency of an internal combustion engine wherein the engine comprises a crankshaft, one or more cylinders including a cylinder head, a piston, a combustion chamber, one or more intake valves operated in accordance with late and/or early Miller-type valve timing, one or more exhaust valves, an intake system configured for feeding intake air to the engine, an exhaust system configured for conveying exhaust gas away from the engine, an exhaust gas recirculation (EGR) system including a gas feeding device in the form of a displacement pump connected to an EGR chive unit, wherein the gas feeding device is configured to feed exhaust gas branched off from the exhaust system through an EGR conduit and, downstream the gas feeding device, feed the branched off exhaust gas into the intake system, the engine further comprising a pressure charging system connected to the intake system characterized in that the method includes the steps of:

• Operating the internal combustion engine under such conditions that the pressure in the intake system exceeds or is substantially similar to the pressure in the exhaust system, and
• Operating the gas feeding device to pressurise and thereby supply branched off exhaust gas to the intake system,
• or
• Operating the internal combustion engine under such conditions that the pressure in the exhaust system is higher than the pressure in the intake system,
• Configuring the EGR system and/or the EGR drive unit to be driven by the gas feeding device so as to generate a power output,
• Operating the engine so as to drive the gas feeding device by means of exhaust gas flowing from the exhaust system to the intake system and thereby operate the gas feeding device in an energy recovery mode where the EGR drive unit generates a power output.