What does 4WD mean for cars?

[KingAnn]

4WD in cars stands for four-wheel drive, which means both the front and rear wheels of the vehicle have driving power. The engine's output torque can be distributed in different proportions to all wheels according to the road conditions, thereby improving the vehicle's driving capability. Four-wheel drive systems are categorized into: 1. Full-time 4WD: The vehicle is always driven by all four wheels independently; 2. Part-time 4WD: The driver can manually switch between two-wheel drive and four-wheel drive modes by engaging or disengaging the transfer case based on road conditions; 3. On-demand 4WD: The system automatically switches between two-wheel drive and four-wheel drive according to the driving conditions, engaging four-wheel drive only when necessary while remaining in two-wheel drive under normal circumstances.