Abstract: Disclosed herein is an exhaust insulator structure for a multi-cylinder engine of a vehicle. The structure includes an exhaust manifold, an exhaust gas purifier, and a heat insulator. The engine is able to switch its mode of operation from an all-cylinder operation in which all of four cylinders thereof are activated to a cylinder-cutoff operation in which two of the four cylinders are deactivated to serve as idle cylinders and the other two cylinders are activated to serve as active cylinders, or vice versa. The exhaust manifold includes: idle-cylinder-connected branched exhaust piping communicating with the idle cylinders; and active-cylinder-connected branched exhaust piping communicating with the active cylinders. A portion of the heat insulator facing the active-cylinder-connected branched exhaust piping has an opening that lets air blowing against the vehicle traveling into the heat insulator.

Abstract: Disclosed herein is an exhaust insulator structure for a multi-cylinder engine of a vehicle. The structure includes an exhaust manifold, an exhaust gas purifier, and a heat insulator. The engine is able to switch its mode of operation from an all-cylinder operation in which all of four cylinders thereof are activated to a cylinder-cutoff operation in which two of the four cylinders are deactivated to serve as idle cylinders and the other two cylinders are activated to serve as active cylinders, or vice versa. The exhaust manifold includes: idle-cylinder-connected branched exhaust piping communicating with the idle cylinders; and active-cylinder-connected branched exhaust piping communicating with the active cylinders. A portion of the heat insulator facing the active-cylinder-connected branched exhaust piping has an opening that lets air blowing against the vehicle traveling into the heat insulator.