Engine system

An engine system, comprising:

• an engine including:
• a cylinder defining a combustion chamber;
• a piston configured to reciprocate inside the cylinder;
• and
• a fuel injection valve configured to directly inject fuel into the cylinder;
• a swirl control valve provided inside an intake passage and configured to generate a swirl flow inside the cylinder when the swirl control valve closes, the intake passage being configured to supply intake air to the cylinder;
• an exhaust gas recirculation (EGR) passage configured to recirculate exhaust gas of the engine as EGR gas to the intake passage;
• an EGR gas adjusting mechanism provided to the EGR passage and configured to control an amount of EGR gas to be recirculated to the intake passage;
• and
• a controller configured to control the fuel injection valve, the swirl control valve, and the EGR gas adjusting mechanism,
• wherein when an engine load is at or below a given threshold, the controller controls the swirl control valve to close, and
• wherein while the engine load is at or below the threshold, the controller controls the EGR gas adjusting mechanism such that, at a fixed engine speed, an increase rate of the amount of EGR gas with respect to an increase in the engine load is lower in a first load range than in a second load range, the first load range being higher than the second load range and including the threshold.