4H and 4L in SUVs and Trucks: When and How to Use Them?

Four-wheel drive (4WD) and all-wheel drive (AWD) systems have become increasingly popular in SUVs and trucks, offering improved traction and stability in various driving conditions.

Two key features in these systems are 4H (4 High) and 4L (4 Low), each designed for specific purposes. In this article, we will explore what 4H and 4L mean, provide examples of popular SUVs and trucks that offer these features, discuss their pros and cons, explain how to know when to engage them, and highlight the differences between 4WD and AWD.

What are 4H and 4L?

4H (4 High) and 4L (4 Low) are settings in 4WD and AWD systems that determine how power is distributed to the vehicle’s wheels.

• 4H (4 High): This mode is typically used for regular driving conditions on paved roads or in slippery conditions like rain or light snow. It provides power to all four wheels, improving traction and stability during acceleration and in slippery conditions.
• 4L (4 Low): 4L is intended for more challenging off-road conditions or situations that require maximum traction and power, such as steep inclines, deep mud, rocks, or deep snow. It provides maximum torque and power to all four wheels, allowing for slower speeds and better control in extreme off-road situations.

Popular SUVs and Trucks with 4H and 4L:

Many SUVs and trucks offer 4H and 4L settings. Here are a few examples:

1. Jeep Wrangler: The Jeep Wrangler is renowned for its off-road capabilities and offers both 4H and 4L settings. Drivers can engage 4H for regular off-road adventures and switch to 4L for more challenging terrain.
2. Toyota Land Cruiser: The Land Cruiser is a legendary off-roader with 4H and 4L modes. It excels in demanding conditions and offers robust off-road capabilities.
3. Ford F-150 Raptor: As a high-performance off-road truck, the F-150 Raptor features both 4H and 4L settings. It’s designed for enthusiasts who want to tackle tough terrain with ease.

Pros and Cons of 4H and 4L:

Pros:

• Improved traction: Both 4H and 4L modes enhance traction and stability, reducing the likelihood of wheel slippage.
• Off-road capabilities: 4L, in particular, allows vehicles to conquer challenging off-road obstacles and steep inclines.
• Versatility: SUVs and trucks equipped with these modes are suitable for a wide range of driving conditions, from everyday commuting to extreme off-roading.

Cons:

• Reduced fuel efficiency: Engaging 4WD modes can increase fuel consumption, especially in 4L mode, due to higher power requirements.
• Limited use on dry, paved roads: Using 4L on regular roads can strain the drivetrain and may cause damage. It should only be engaged when necessary.
• Added complexity: 4WD systems can be more complex and costly to maintain compared to two-wheel-drive vehicles.

How to Know When to Engage 4H or 4L:

1. Road Conditions: Use 4H on slippery or wet roads, such as during rain or light snow. Reserve 4L for challenging off-road conditions like mud, rocks, or deep snow.
2. Terrain: Consider the terrain you’re about to traverse. If you’re tackling steep inclines, rocky paths, or deep mud, 4L is likely the better choice.
3. Vehicle Manual: Always consult your vehicle’s owner’s manual for specific recommendations regarding when to engage 4H or 4L. Manufacturers provide guidelines to ensure safe and efficient operation.

4WD vs. AWD: Understanding the Difference

It’s important to distinguish between 4WD and AWD systems:

• 4WD: Primarily found in trucks and SUVs, 4WD systems are typically selectable and designed for more demanding off-road use. The driver can engage or disengage 4WD modes as needed.
• AWD: AWD systems are more common in passenger cars and some SUVs. They operate automatically, distributing power to all wheels as necessary for improved traction. AWD is ideal for on-road use and light off-roading but may not be as robust as 4WD in extreme off-road conditions.

Difference Between 4H And AWD

4H (4 High) and all-wheel drive (AWD) are both drivetrain options that improve a vehicle’s traction and stability, but they differ in several key ways:

1. Selectivity:
   • 4H: 4H is typically found in vehicles with four-wheel drive (4WD) systems, often in trucks and some SUVs. It’s a selectable mode that the driver can engage when needed, primarily for off-road use or when encountering slippery conditions. In 4H mode, power is distributed to all four wheels.
   • AWD: AWD is a drivetrain system commonly found in a wide range of vehicles, including SUVs and passenger cars. It operates automatically, continuously distributing power to all wheels as needed based on real-time traction conditions. AWD systems are always active, and the driver has no control over when or how power is sent to the wheels.
2. Purpose:
   • 4H: 4H is designed for specific scenarios where extra traction and control are required. It’s often used during off-road adventures, when driving on rough terrain, climbing steep inclines, or traversing challenging obstacles. It can also be engaged in slippery on-road conditions like snow or mud.
   • AWD: AWD is primarily intended for on-road use, enhancing traction and stability on wet, icy, or uneven surfaces. It is well-suited for everyday driving, especially in adverse weather conditions, where it can automatically adjust power distribution to optimize grip.
3. Control:
   • 4H: The driver can manually engage or disengage 4H as needed, typically using a lever or switch. This control allows the driver to choose when to use the extra traction and power provided by all four wheels.
   • AWD: AWD operates without driver intervention. The system’s sensors and computer determine how much power to send to each wheel based on traction conditions, making it a seamless and user-friendly option for daily driving.
4. Fuel Efficiency:
   • 4H: Engaging 4H can result in increased fuel consumption because it sends power to all four wheels, even when it’s not necessarily needed for on-road driving.
   • AWD: AWD systems are generally more fuel-efficient than 4WD systems because they only send power to the wheels that require it, optimizing fuel economy during regular driving conditions.

In summary, while both 4H and AWD enhance traction and stability, 4H is a selectable mode typically found in 4WD vehicles and is intended for off-road use or challenging on-road conditions. AWD, on the other hand, is an automatic system suitable for everyday driving on various surfaces, offering improved traction without the need for driver intervention. Your choice between the two should depend on your specific driving needs and the type of terrain and conditions you encounter regularly.

FAQs

Q1: What is 4H in a vehicle, and when should I use it?

• A: 4H stands for “4 High,” and it’s a four-wheel drive (4WD) setting that distributes power to all four wheels for improved traction. It is commonly used in off-road situations, on slippery surfaces like mud or snow, and when you need extra traction while driving at regular speeds.

Q2: What is 4L, and when should I engage it?

• A: 4L stands for “4 Low,” and it’s another 4WD setting used for maximum traction and power at lower speeds. You should engage 4L when navigating steep inclines, deep mud, rocky terrain, or other challenging off-road conditions that require slow and controlled movement.

Q3: Is it okay to use 4L on regular roads?

• A: No, it’s generally not recommended to use 4L on regular paved roads. Engaging 4L on smooth surfaces can strain the drivetrain and may cause damage. Reserve 4L for off-road or extreme conditions only.

Q4: What is all-wheel drive (AWD), and how does it differ from 4WD?

• A: AWD is a drivetrain system that automatically distributes power to all wheels as needed, enhancing traction and stability on various road surfaces. Unlike 4WD, AWD systems do not have selectable 4H or 4L modes, and they are typically designed for on-road use, including adverse weather conditions.

Q5: Are AWD and 4WD the same thing?

• A: No, AWD and 4WD are not the same. AWD systems are designed for automatic, all-weather traction and are often found in passenger cars and some SUVs. 4WD systems, on the other hand, are typically found in trucks and some SUVs, offering selectable 4H and 4L modes for off-road or challenging driving conditions.

Q6: Can I switch between 4H and 4L while driving?

• A: It depends on your vehicle’s design. Some 4WD systems allow you to switch between 4H and 4L while moving at low speeds, while others may require you to come to a complete stop or engage the vehicle’s neutral position before making the switch. Refer to your owner’s manual for specific instructions.

Q7: Do I need to engage AWD, or does it work automatically?

• A: AWD systems operate automatically, adjusting power distribution to the wheels based on real-time traction conditions. There’s typically no need for driver intervention, making AWD a convenient option for daily driving.

Q8: Are AWD vehicles suitable for off-roading like 4WD vehicles?

• A: AWD systems are generally not as robust as 4WD systems for extreme off-roading. While they provide good traction on various surfaces, 4WD vehicles with selectable 4H and 4L modes are better suited for challenging off-road conditions and steep terrain.

Q9: Does using 4H or 4L affect fuel efficiency?

• A: Yes, engaging 4H or 4L can impact fuel efficiency. 4H typically has a smaller impact than 4L, but both modes can increase fuel consumption compared to driving in 2WD or AWD mode. It’s best to use these modes only when necessary.

Q10: How can I tell if my vehicle has 4H, 4L, or AWD capabilities?

• A: Check your vehicle’s owner’s manual or consult the manufacturer’s specifications to determine if your vehicle is equipped with 4H, 4L, or AWD. Additionally, look for controls or switches inside the vehicle that allow you to engage these modes, if applicable.

Conclusion

In SUVs and trucks, 4H and 4L settings are valuable tools that enhance traction, stability, and off-road capabilities. While they offer numerous advantages, drivers should use them judiciously, following manufacturer recommendations and considering road and terrain conditions. Understanding the difference between 4WD and AWD is essential to choose the right vehicle for your specific needs, whether it’s everyday commuting or conquering rugged off-road terrain.