A method includes operating a spark ignition engine and flowing low pressure exhaust gas recirculation (EGR) from an exhaust to an inlet of the spark ignition engine. The method includes interpreting a parameter affecting an operation of the spark ignition engine, and determining a knock index value in response to the parameter. The method further includes reducing a likelihood of engine knock in response to the knock index value exceeding a knock threshold value.

A vehicle engine 2 comprises an exhaust system having an exhaust manifold 12 and an exhaust purification device 18. The exhaust manifold 12 is disposed at a predetermined distance from a dash panel 106 constituting a body of the vehicle 100, the exhaust purification device 18 is disposed in a position overlapping a floor tunnel region 114, formed by a floor tunnel of the body, and is disposed below the exhaust manifold 12 and to one side of the center of the engine 2 in the cylinder-array direction, as viewed from the longitudinal direction of the vehicle 100. An exhaust purification device introduction passage 17 connecting the exhaust manifold 12 and the exhaust purification device 18 is disposed on the other side of the center of the exhaust manifold 12 in the cylinder-array direction, and extends below the exhaust manifold 12 to be connected to the exhaust purification device 18.

A vehicle engine 2 comprises an exhaust system having an exhaust manifold 12 and an exhaust purification device 18. The exhaust manifold 12 is disposed at a predetermined distance from a dash panel 106 constituting a body of the vehicle 100, the exhaust purification device 18 is disposed in a position overlapping a floor tunnel region 114, formed by a floor tunnel of the body, and is disposed below the exhaust manifold 12 and to one side of the center of the engine 2 in the cylinder-array direction, as viewed from the longitudinal direction of the vehicle 100. An exhaust purification device introduction passage 17 connecting the exhaust manifold 12 and the exhaust purification device 18 is disposed on the other side of the center of the exhaust manifold 12 in the cylinder-array direction, and extends below the exhaust manifold 12 to be connected to the exhaust purification device 18.

Various systems and methods are provided for exhaust gas recirculation. In one example, an exhaust gas recirculation (EGR) system includes an EGR passage coupling an engine exhaust system to an engine intake system, an EGR cooler positioned in the EGR passage, a recirculation passage coupling an outlet of the EGR cooler to an inlet of the EGR cooler, an EGR cooler recirculation valve positioned in the recirculation passage and controllable to change a flow of exhaust gas though the recirculation passage, and a controller configured to adjust a position of the EGR cooler recirculation valve based on a temperature at the inlet of the EGR cooler.

Various systems and methods are provided for exhaust gas recirculation. In one example, an exhaust gas recirculation (EGR) system includes an EGR passage coupling an engine exhaust system to an engine intake system, an EGR cooler positioned in the EGR passage, a recirculation passage coupling an outlet of the EGR cooler to an inlet of the EGR cooler, an EGR cooler recirculation valve positioned in the recirculation passage and controllable to change a flow of exhaust gas though the recirculation passage, and a controller configured to adjust a position of the EGR cooler recirculation valve based on a temperature at the inlet of the EGR cooler.

An air intake heater system for a combustion engine, comprising; a turbocharger, a high pressure EGR conduit, a low pressure EGR conduit, and an air intake conduit, where the system comprises a heat exchanger arranged upstream of the turbocharger, where the heat exchanger comprises a first flow channel connecting an air inlet to an inlet of the turbocharger and a second flow channel, where the second flow channel is part of the high pressure EGR conduit. The advantage of the invention is that intake air and low pressure EGR gas can be heated by the high pressure EGR gas, and that high pressure EGR gas can be cooled by intake air.

An intercooler cooling apparatus is provided. The apparatus cools an intercooler installed between a compressor of a turbocharger and an engine to adjust an oil temperature. The apparatus includes a water tank that surrounds a part of an outer side of the intercooler, in which cooling water discharged from the engine flows into a first side to exchange heat with the intercooler and the cooling water is discharged through a second side. An ATF warmer and an air conditioner refrigerant line are also installed in the water tank, in which oil of a transmission is circulated.

An intercooler cooling apparatus is provided. The apparatus cools an intercooler installed between a compressor of a turbocharger and an engine to adjust an oil temperature. The apparatus includes a water tank that surrounds a part of an outer side of the intercooler, in which cooling water discharged from the engine flows into a first side to exchange heat with the intercooler and the cooling water is discharged through a second side. An ATF warmer and an air conditioner refrigerant line are also installed in the water tank, in which oil of a transmission is circulated.

An exhaust system device (1) for a vehicle (100) comprises an exhaust purification device (18) and a first exhaust gas recirculation (EGR) cooler (24). The exhaust purification device (18) is disposed with a central axis of a downstream-side end inclined downwardly toward a rear side of the vehicle (100). The EGR cooler (24) is provided so as to introduce exhaust from a downstream side of the exhaust purification device (18), is adjacent to the exhaust purification device (18) and fixed to the exhaust purification device (18), and is disposed such that a central axis of the EGR cooler (24) is inclined downwardly toward the rear side of the vehicle.

An exhaust system device (1) for a vehicle (100) comprises an exhaust purification device (18) and a first exhaust gas recirculation (EGR) cooler (24). The exhaust purification device (18) is disposed with a central axis of a downstream-side end inclined downwardly toward a rear side of the vehicle (100). The EGR cooler (24) is provided so as to introduce exhaust from a downstream side of the exhaust purification device (18), is adjacent to the exhaust purification device (18) and fixed to the exhaust purification device (18), and is disposed such that a central axis of the EGR cooler (24) is inclined downwardly toward the rear side of the vehicle.