Should you drive in H4 or L4?
When it comes to driving in different terrain or weather conditions, the choice between H4 (high 4-wheel drive) and L4 (low 4-wheel drive) can make a significant difference in your vehicle's performance and your safety. In this article, we'll explore the key factors to consider when deciding between H4 and L4 driving modes.
What is H4 and L4 Driving?
H4 (high 4-wheel drive) and L4 (low 4-wheel drive) are two different modes of four-wheel drive (4WD) operation in vehicles. H4 is typically used for normal on-road driving, while L4 is designed for more challenging off-road conditions or when extra traction is required.
- H4 (High 4-Wheel Drive): This mode provides power to all four wheels, but the gear ratio is optimized for normal on-road driving. H4 is suitable for driving on paved roads, light off-road conditions, and mild inclines.
- L4 (Low 4-Wheel Drive): This mode also provides power to all four wheels, but the gear ratio is lower, providing more torque and traction for navigating steep hills, deep mud, sand, or other challenging off-road terrain.
The choice between H4 and L4 depends on the driving conditions and the specific needs of your vehicle and journey.
When to Use H4 vs. L4
The decision to use H4 or L4 should be based on the terrain, weather conditions, and the capabilities of your vehicle.
Use H4 When:
- Driving on paved roads or light off-road conditions
- Navigating mild inclines or hills
- Towing a trailer or hauling a heavy load
- Driving in normal weather conditions, such as dry or wet pavement
H4 is the recommended mode for most everyday driving situations, as it provides the best balance of traction, fuel efficiency, and drivability.
Use L4 When:
- Driving in challenging off-road conditions, such as deep mud, sand, or steep inclines
- Navigating through deep snow or ice
- Towing a heavy load or trailer in difficult terrain
- Requiring maximum traction and torque for specific driving tasks
L4 should be used when extra traction and power are needed to overcome obstacles or maintain control in extreme driving conditions.
Switching Between H4 and L4
Most modern 4WD vehicles allow you to switch between H4 and L4 while driving, but it's important to follow the manufacturer's instructions and recommendations. Typically, you'll need to come to a complete stop and shift the transfer case into the desired mode. Attempting to switch between H4 and L4 while in motion can damage the drivetrain.
Remember, the choice between H4 and L4 is crucial for your safety and the performance of your vehicle. Always consider the driving conditions, your vehicle's capabilities, and the specific task at hand when deciding which mode to use.
Is it OK to drive in 4H on the highway?
It is okay to drive in 4H on the highway if the road surface is slippery, like on wet, icy, or snowy roads, but not on dry, hard pavement. Using 4H on dry surfaces can cause drivetrain binding, increased tire wear, and potential damage to your vehicle. You should switch back to 2H when the slippery conditions end, and you are on dry roads.
When to use 4H
- Slippery surfaces: Use 4H for driving on wet, icy, or snowy roads, as well as on loose gravel or packed sand.
- Normal highway speeds: 4H is for use at normal highway speeds, unlike 4L which is for low-speed, high-power situations.
When NOT to use 4H
- Dry, hard pavement: Do not use 4H on dry, normal, paved roads, as it can cause damage.
- Tight turns: On a dry surface, it's crucial to switch to 2H for turns because the front and rear axles rotate at different speeds, which is restricted in 4H and can cause the drivetrain to bind.
How to use 4H
- Check your manual: Always check your vehicle's manual for specific recommendations and limitations for its 4WD system.
- Switch back to 2H: As soon as the road surface becomes dry and traction improves, switch back to 2H to avoid unnecessary wear and tear.
- Be mindful of conditions: While some newer vehicles have "full-time" or "automatic" 4WD systems that are designed for use on dry roads, traditional "part-time" systems require you to manually switch between 2H and 4H based on traction needs.
Is 4H or 4L better for regular driving?
Use 4H for slippery Irvine roads where you need traction without slowing down. Use 4L for slow, technical driving where maximum power is essential. Avoid using 4WD on dry pavement—it can cause drivetrain damage.
Should I be driving in H4 or L4?
I use H4 every time I'm driving in snow or when the dirt road conditions require it. I leave it in H4 when driving during active snowstorms before the plows arrive. I only use L4 when necessary on a tricky trail situation.
Should I drive in H4 or L4 in snow?
4Lo, or 4 Low, is the high-torque four-wheel drive setting. 4Lo is meant to be used only on very rough terrain, such as thick mud, heavy snow, or fording a river. If you are wondering whether to use 4H or 4L for snow, you should use 4Lo in deep snow. When in 4Lo, you should never go above 40 mph.
