Method for controlling engine clutch of vehicle

A vehicle comprising:

• an engine and a motor;
• an engine clutch mounted between the engine and the motor and selectively transmitting engine power therebetween;
• and
• a controller including a processor and a non-transitory storage medium containing program instructions that, when executed by the processor, perform:
• checking whether a driving mode of the vehicle has been selected as a terrain mode;
• checking whether a variation of a number of revolutions per hour of the engine is greater than a first reference value and whether a usage rate of electrical energy per hour of the motor is greater than a second reference value, upon determining that the terrain mode has been selected;
• adjusting an engagement condition of the engine clutch for launch acceleration, upon determining that the variation of the number of revolutions per hour of the engine is greater than the first reference value and the usage rate of electrical energy per hour of the motor is greater than the second reference value;
• and
• engaging the engine clutch through a launch engagement control when the engagement condition of the engine clutch for launch acceleration is adjusted.