Should the handbrake be engaged when the P gear is already on?

[DelAriel]

Engaging the handbrake is still necessary when the P gear is on. Below are the specific details: 1. P gear: P gear = Parking, which means stopping (for example, parking). When the gear shift lever is in this position, the parking lock mechanism locks the transmission output shaft. In P gear, the drive shaft is partially locked inside the transmission, so even without pressing the brake pedal, the vehicle has a certain braking force on flat ground. 2. Handbrake: The professional term for the handbrake is auxiliary brake. Unlike the principle of the main brake, it uses a steel cable connected to the rear brake shoes to apply braking force to the vehicle. Long-term use of the handbrake can cause plastic deformation of the steel cable. Since this deformation is irreversible, prolonged use will reduce its effectiveness, and the handbrake's travel distance will increase. Springs are also used in conjunction with the handbrake. When the handbrake is engaged, the springs are stretched; when the handbrake is released, the springs return to their original length. Long-term use of the handbrake can also cause corresponding deformation of the springs.