Abstract: An internal-combustion engine includes a variable compression ratio mechanism for changing a mechanical compression ratio, and a variable valve timing mechanism for changing the valve timing of an intake valve. When acceleration is demanded, a target compression ratio is set to a lower compression ratio than the target value in a normal condition, and the valve timing is set to the advance angle side. Since the allowable combustion pressure decreases in a prescribed intermediate compression ratio region, if an actual compression ratio exists in the prescribed intermediate compression ratio region in the course of a compression ratio change accompanying acceleration, the variable compression ratio mechanism restricts the intake pressure by increasing a degree of opening of a wastegate valve or reducing a degree of opening of a throttle valve, for example.

Abstract: An internal-combustion engine includes a variable compression ratio mechanism for changing a mechanical compression ratio, and a variable valve timing mechanism for changing the valve timing of an intake valve. When acceleration is demanded, a target compression ratio is set to a lower compression ratio than the target value in a normal condition, and the valve timing is set to the advance angle side. Since the allowable combustion pressure decreases in a prescribed intermediate compression ratio region, if an actual compression ratio exists in the prescribed intermediate compression ratio region in the course of a compression ratio change accompanying acceleration, the variable compression ratio mechanism restricts the intake pressure by increasing a degree of opening of a wastegate valve or reducing a degree of opening of a throttle valve, for example.

Abstract: A control method for an internal combustion engine including a variable compression ratio mechanism which includes: implementing a compression ratio fixing control in which a mechanical compression ratio is fixed to a predetermined low compression ratio, and controlling combustion form in a cylinder to stratified combustion, under engine idling during catalyst warming-up; controlling the combustion form in the cylinder to homogeneous combustion, under an operation state other than the engine idling during the catalyst warming-up; and implementing the compression ratio fixing control and controlling the combustion form in the cylinder to the homogeneous combustion, in response to pressing-down of an accelerator under the engine idling during the catalyst warming-up, and as long as the engine idling during the catalyst warming-up has a possibility to resume in response to release of the accelerator after the pressing-down.

Abstract: A control method for an internal combustion engine including a variable compression ratio mechanism which includes: implementing a compression ratio fixing control in which a mechanical compression ratio is fixed to a predetermined low compression ratio, and controlling combustion form in a cylinder to stratified combustion, under engine idling during catalyst warming-up; controlling the combustion form in the cylinder to homogeneous combustion, under an operation state other than the engine idling during the catalyst warming-up; and implementing the compression ratio fixing control and controlling the combustion form in the cylinder to the homogeneous combustion, in response to pressing-down of an accelerator under the engine idling during the catalyst warming-up, and as long as the engine idling during the catalyst warming-up has a possibility to resume in response to release of the accelerator after the pressing-down.

Abstract: A method for controlling a vehicle system includes receiving, at a control system, a request to open an ambient air inlet valve of a vehicle component, wherein the ambient air inlet valve is operable to move from a closed position to an open position in response to an open signal that is transmitted to the ambient air inlet valve from the control system. The method also includes determining whether a towing condition is present, determining whether at least one submergence risk criterion is present, and transmitting the open signal to the ambient air inlet valve, in response to the request to open the ambient air inlet valve, if the towing condition is not present or the at least one submergence risk criterion is not present.

Abstract: A method for controlling a vehicle system includes receiving, at a control system, a request to open an ambient air inlet valve of a vehicle component, wherein the ambient air inlet valve is operable to move from a closed position to an open position in response to an open signal that is transmitted to the ambient air inlet valve from the control system. The method also includes determining whether a towing condition is present, determining whether at least one submergence risk criterion is present, and transmitting the open signal to the ambient air inlet valve, in response to the request to open the ambient air inlet valve, if the towing condition is not present or the at least one submergence risk criterion is not present.