A spark ignition gasoline engine, control method thereof, control device and computer program product

A spark ignition gasoline engine (1), comprising: an engine body (11, 12) having at least one cylinder (18), the geometric compression ratio is about 14: 1 or set it to be supplied with fuel containing at least gasoline; a fuel injection valve (67) for injecting the fuel into the cylinder (18); a spark plug (25) which is arranged such that it inside the cylinder (18) is oriented, and in order to ignite the air-fuel mixture in the cylinder (18); a fuel pressure varying mechanism for changing a pressure of the fuel, which is injected from the fuel injection valve (67); and a controller (10) for operating the engine body (11, 12) by at least the fuel injection valve (67), the spark plug (25) and the fuel pressure varying mechanism to be controlled or regulated, wherein the controller (10) when an operating state of the engine body (11, 12) in a low engine speed range, controls the fuel pressure varying mechanism or regulates, so that the fuel pressure is higher in a high engine load range in comparison to a low engine load range, the controller (10 ), the fuel injection valve (67) operates in the high engine load range, to perform a plurality of fuel injections, at least at a time that is more retarded than an injection time of the fuel in the low engine load range and in a delay time period from the late stage of a compression stroke up to the early is, phase of an expansion stroke, and the controller (10) operates the spark plug (25) in the high engine load range to ignite at a time during the delay time and after the fuel injection.