Which kind of 4x4 system requires manual driver activation or deactivation?

The part-time 4x4 system requires manual driver activation or deactivation, making it distinct from the other types of systems. In a part-time system, the driver must engage and disengage the four-wheel drive mode based on the driving conditions. This is particularly beneficial in scenarios where off-road traction is necessary, or when navigating difficult terrain, as it allows the driver to actively choose when to utilize 4x4 capabilities.

The user must remember to switch back to two-wheel drive when conditions improve to optimize fuel efficiency and reduce wear on the drivetrain. This level of driver involvement is a defining feature of part-time systems, making them ideal for dedicated off-road enthusiasts or those who may not require 4x4 capabilities at all times.

In contrast, full-time systems automatically distribute power to all four wheels at all times without the need for manual intervention. On-demand systems activate four-wheel drive automatically when slip is detected, while automatic systems do so seamlessly, allowing for a more hands-off driving experience.