Control device

A hybrid electric vehicle, comprising:

• an engine including a particulate filter provided in an exhaust passage;
• an oil pan that stores oil;
• a motor generator serving as a drive source different from the engine;
• an occupant detection sensor configured to detect an occupant;
• and
• a processor configured to:
• perform a dilution amount calculation process that calculates a dilution amount of the oil stored in the oil pan;
• perform a deposition amount calculation process that calculates a deposition amount of particulate matter deposited on the particulate filter;
• perform an occupant number acquisition process that acquires a number of occupants based on a detection result from the occupant detection sensor;
• determine whether the hybrid electric vehicle is in an electric driving state in which the hybrid electric vehicle is traveling using a driving force of the motor generator without operating the engine;
• upon a determination that the hybrid electric vehicle is in the electric driving state, perform start-up control that starts the engine in response to satisfaction of an execution condition that is satisfaction of at least either of a condition that the dilution amount exceeds a specified dilution amount determined in advance and a condition that the deposition amount exceeds a specified deposition amount determined in advance;
• and
• perform relaxation control that relaxes the execution condition when the number of occupants is a first number compared to the execution condition when the number of occupants is a second number larger than the first number, wherein:
• the first number is one or greater.