When an incremental amount of a steering angle exceeds a reference incremental amount, an ECU 60 executes vehicle attitude control of reducing an output torque of an engine, and, in a given operating range, drives a spark plug 16 to allow an air-fuel mixture to be self-ignited at a given timing, thereby executing SPCCI combustion. When there is a request for an additional deceleration from the vehicle attitude control (#12: YES) and the SPCCI combustion is performed (#13: YES), the ECU 60 prohibits ignition retardation and performs torque reduction for the vehicle attitude control, by fuel amount reduction control of reducing the amount of fuel to be supplied into a cylinder 2 (#14). On the other hand, when the SPCCI combustion is not performed (NO in #13), the ECU 60 performs the ignition retardation to attain the torque reduction for the vehicle attitude control (#15).