The differences between full-time four-wheel drive and on-demand four-wheel drive are: Different operating states: Full-time four-wheel drive maintains four-wheel drive at all times, while on-demand four-wheel drive activates four-wheel drive mode only when needed, typically operating in two-wheel drive mode under normal conditions. Different structures: Compared to full-time four-wheel drive, on-demand four-wheel drive has a simpler structure. Due to its unique design, it is more suitable for vehicles with front transverse engine and front-wheel drive platforms. Different power transmission: Currently, on-demand four-wheel drive is limited by its structural shortcomings when transmitting power between the front and rear axles, unable to deliver more than 50% of the power to the rear axle. This results in a smaller adjustment range for active safety control compared to full-time four-wheel drive. Different off-road capabilities: On-demand four-wheel drive uses a lower-grade viscous coupling center differential, making the structure simpler, more cost-effective, and more fuel-efficient. Vehicles with on-demand four-wheel drive have similar fuel consumption to regular two-wheel drive vehicles. On-demand four-wheel drive, also known as real-time four-wheel drive, is controlled by a computer chip that switches between two-wheel drive and four-wheel drive. It can automatically identify driving conditions and switch modes based on changes in the environment. On rough, hilly, or slippery roads with low traction, the vehicle automatically sets to four-wheel drive mode, while on flat urban roads, it switches back to two-wheel drive. Full-time four-wheel drive vehicles maintain traction on all four tires at all times, with each tire independently distributing power and receiving equal torque. There is no concern about losing power. Additionally, the differential can distribute torque to a stable ratio, enhancing tire drive and anti-slip performance. The vehicle remains in four-wheel drive mode throughout the entire driving process without requiring system control or scenario judgment. It offers better off-road and handling performance, greater stability, and can adapt to snowy and slippery roads, but it consumes more fuel and has poorer fuel economy.
