What do 4H and 4L mean in four-wheel drive vehicles?

[DeMarley]

In four-wheel drive vehicles, 4H stands for high-range four-wheel drive, while 4L stands for low-range four-wheel drive. 4H offers strong stability, traction, and handling performance, and in this mode, the vehicle's speed should be kept below 100 kilometers per hour. 4L provides high torque and is suitable for extreme off-road conditions, such as climbing steep slopes, off-roading, traversing swamps, deserts, and other harsh environments. A four-wheel drive vehicle is equipped with front and rear differentials that link all four wheels for power distribution. Since the engine's power is transmitted to all four tires, all wheels can provide traction. In contrast, a regular two-wheel drive vehicle may lose power in all driving wheels if one of them slips.

[SanVincent]

When I first started driving a 4WD vehicle, I was also curious about what 4H and 4L meant. Later, a friend told me that 4H stands for high-speed four-wheel drive mode, generally used on paved roads or during rainy and snowy weather to make the car more stable and less prone to skidding. On the other hand, 4L is the low-speed four-wheel drive mode, specifically designed for off-road situations like climbing steep slopes or driving through mud, increasing torque to allow the engine to output more power but at a slower speed. I tried it once in the countryside when I encountered rough terrain; switching to 4L made it easy to get through. However, I had to switch back to 4H afterward to avoid wasting fuel. Remember not to use 4L on good roads for too long, as it could damage the drivetrain. Overall, these two switches are thoughtfully designed, allowing flexible adjustments based on different road conditions. I often use them now while driving, especially during winter trips for added safety.

[LeEsther]

As a seasoned off-road enthusiast, 4H and 4L are my most familiar companions. 4H refers to high-range four-wheel drive mode, activated at higher speeds, ideal for slippery or loose surfaces like snow and sand, enhancing traction; 4L is low-range four-wheel drive mode, reducing speed but multiplying engine torque, especially effective for steep rocks or deep mud pits. I used 4L to climb slopes when leading mountain expeditions, with no slipping at all. The key is timely switching—for example, select 4H for highway driving after startup, then switch to 4L when encountering obstacles, ensuring decisive operation. Additionally, modern vehicle systems are more intelligent, automatically detecting road conditions to prevent misuse by novices, significantly reducing the risk of malfunctions.

[Wayne]

When taking my kids out for a trip, I always pay attention to how to use the 4H and 4L modes in our family's 4WD vehicle, as it's crucial for driving safety. 4H is the high-speed four-wheel drive mode, suitable for daily driving on national highways or rainy days to ensure stable driving. 4L is the low-speed four-wheel drive mode, used to overcome the risk of steep slopes and slipping when driving on mountain roads or off-road sections, but it should not be used on urban roads to avoid damaging the components. Once, on a muddy road back to my hometown, I tried 4L and it performed steadily, but it's essential to drive at low speeds. It's recommended to familiarize yourself with the switching instructions in the vehicle manual before driving and not to act recklessly to protect everyone in the car. After all, these designs are essentially protective mechanisms, and proper use can prevent accidents.

[MacLila]

I learned a bit about car repair before. 4H and 4L are actually part of a part-time four-wheel drive system. 4H refers to the high-speed mode where the engine drives all four wheels synchronously, with power evenly distributed and relatively low fuel consumption, suitable for most terrains. 4L, on the other hand, is the low-speed mode, which reduces the gear ratio of the transfer case to increase torque for rough roads, but requires short-term use due to higher engine RPM. In principle, it's like amplifying torque through mechanical structures, making it ideal for off-road challenges. In practical operation, I've experienced different scenarios, such as switching to 4H on snowy roads to prevent skidding, while switching to 4L in rocky areas makes climbing easier, with system stability being a highlight.