4WD controls explained: How to use 2H, 4H, 4L and diff locks

The world of four-wheel-drive vehicles can be overwhelming for many buyers, especially when trying to distinguish between the different capabilities of utes and SUVs.

Both styles of vehicles are popular, but a lot of buyers don’t understand how to use the controls that come with their vehicles.

We’ve chosen the 2025 Mitsubishi Triton with Super Select 4WD to run through the differences between all the common four-wheel drive modes and how and when to use differential locks (and when not to use them!).

Ute and SUV differences

Most dual-cab utes on the market, such as the Toyota HiLux and Isuzu D-Max, are designed to be daily-driven in two-wheel drive (2WD) mode, specifically rear-wheel drive (RWD).

This setup is efficient for urban commutes and light-duty tasks. When venturing off-road, drivers can switch to four-wheel-drive modes, but typically these modes can’t be used on sealed surfaces such as bitumen – more on why later.

However, there are exceptions to this norm. Vehicles like theMitsubishi Triton, GWM Cannon and certain grades of Ford Ranger and Volkswagen Amarok, on the other hand, include a permanent four-wheel drive option that allows drivers to engage four-wheel drive on sealed roads without running the risk of driveline damage.

Most all-wheel drive SUVs offer on-demand all-wheel drive, or a permanent all-wheel drive system that’s capable of working across all surfaces.

An on-demand system works as a two-wheel drive most of the time, only engaging its second axle when slip is detected on the first axle. Some of these SUVs have a setting that locks them in a permanent four-wheel drive mode.

Two-wheel drive high range

Most dual-cab utes are designed to operate in 2H mode during everyday driving. In this mode, only the rear wheels are powered, making the ute function like a traditional rear-wheel-drive vehicle.

The advantage of leaving a vehicle in two-wheel drive (even when equipped with four-wheel drive) is that you use less fuel due to only one axle requiring torque.

Here’s how it works:

• The drivetrain sends power exclusively to the rear axle
• The ute either uses an open differential or a limited-slip differential to manage torque between the rear wheels
• Modern traction control systems also assist in maintaining traction by reducing wheel spin

However, when driving off-road, 2H mode offers the least traction. For example, if one of the rear wheels loses contact with the ground, an open differential will direct all available torque to the wheel with the least resistance—typically the wheel in the air.

In such cases:

• Traction control can intervene to pulse torque to the grounded wheel, helping the vehicle regain momentum
• Turning off traction control in this scenario will cause the elevated wheel to spin freely, leaving the vehicle immobile

To address this limitation, some vehicles offer a rear differential lock, which significantly improves traction.

Rear differential lock

A rear differential lock is a feature designed to split torque equally between the two rear wheels, regardless of traction conditions.

When engaged:

• Both rear wheels rotate at the same speed, ensuring the wheel with traction receives adequate torque
• This feature is invaluable when one wheel is off the ground or slipping on a low-grip surface

Key considerations:

• The rear differential lock must be engaged before encountering challenging terrain, as the vehicle needs to be moving for the lock to engage
• It can generally be used in both 2WD and 4WD modes, but only be used up to a certain speed. Exceeding this speed can automatically disengage the system or risk driveline damage. Some dual-cab utes and SUVs also don’t allow the rear differential lock to work in 2H

The activation button for the rear differential lock often features a diagram of an axle with a “cross” symbol, making it easy to identify on the dashboard or the centre console.

Four-wheel drive high range

Switching to 4WD high-range mode (4H) is ideal for off-road driving where additional traction is needed.

Vehicles like the Mitsubishi Triton can operate in 4H on sealed surfaces, while other vehicles, like the Isuzu D-Max and Toyota HiLux, as an example, can only operate in 4H on unsealed surfaces (more on this later).

• When 4H is engaged in vehicles with on-road 4H functionality, the system will either allow wheels to rotate at different speeds (thus allowing turns on sealed surfaces)
• In vehicles without this functionality, torque is distributed evenly between the front and rear axles by virtue of a centre differential lock or clutch pack
• Some vehicles – like the Mitsubishi Triton, Ford Ranger and Volkswagen Amarok, amongst others – allow operation in 4H both with and without a centre differential lock

This mode is suitable for:

• Loose gravel
• Snow or ice
• Sand or mud

However, it’s important to note that 4H sometimes doesn’t provide cross-axle locking. This means that if one front and one rear wheel lose traction simultaneously, the vehicle may still struggle to maintain momentum.

Traction control plays a vital role in this mode by redistributing torque between the axles, but it may not always be enough in extreme conditions. Pairing 4H mode with a rear differential lock can enhance traction further by ensuring that torque is evenly split across the rear wheels.

Four-wheel drive low range

For the most challenging types of terrain, low-range four-wheel drive (4L) is your go-to mode.

This mode is designed for:

• Steep ascents or descents
• Rock crawling
• Deep mud or sand

The key feature of 4L mode is its reliance on a low-range transfer case, which provides shorter gear ratios for greater torque at low speeds.

This allows the driver to:

• Use engine braking effectively during descents, reducing reliance on the brake pedal
• Maintain control during steep climbs by delivering torque smoothly and evenly without sudden surges

To engage 4L:

1. The vehicle needs to be in neutral
2. You’ll often hear a mechanical “clunk” as the transfer case shifts

This mode also disables systems like stability control and ABS in many vehicles, giving the driver maximum control over the vehicle’s movements in technical scenarios.

Low range effectively multiplies the amount of torque at each wheel. Depending on the vehicle, some dual-cab utes can offer up to 1:60 crawl ratios in low range, effectively multiplying engine torque at the wheels by 60.

You can damage your car by using four-wheel drive on sealed surfaces

One of the most common mistakes new 4WD owners make is engaging four-wheel drive on sealed roads in vehicles that don’t offer that functionality.

Here’s why it’s problematic:

1. Wheel Speed Variations During Turns: When a vehicle turns, the inner wheels travel a shorter distance than the outer wheels, resulting in different rotational speeds. On sealed surfaces, there isn’t enough wheel slip to accommodate these speed variations.
2. Driveline Strain: With the centre or rear differential locked, the vehicle’s driveline attempts to force the wheels to rotate at the same speed. This creates immense strain, as the wheels cannot slip to compensate for the difference in rotational speeds. While when you’re off-road on gravel, for example, there’s enough torque available to overcome friction to rotate the wheel.
3. Potential Damage: Prolonged use of 4WD on sealed surfaces can cause damage to the transmission, transfer case, and/or differentials.

For these reasons, it’s recommended to use 2H mode or AWD systems on sealed roads and reserve 4H, 4L, and differential locks for off-road conditions with sufficient wheel slip.

The exception to that rule is if you’re driving a vehicle equipped with a four-wheel drive system to use on-road, such as select variants of Mitsubishi Triton (with Super Select four-wheel drive), GWM Cannon, Ford Ranger (V6 and some four-cylinder variants) and Volkswagen Amarok (V6 and some four-cylinder variants), as an example.

CarExpert’s Take

Understanding the differences between utes and SUVs, as well as their respective driveline systems, is crucial for maximising performance and minimising wear and tear.

Utes are typically optimised for rear-wheel drive in everyday use, with 4WD modes reserved for specific off-road scenarios (unless equipped to do otherwise).

When using 4WD, remember to select the appropriate mode for the terrain, and if you’re driving a vehicle without 4H support for sealed surfaces always disengage 4WD and differential locks on sealed surfaces to prevent mechanical damage once you get back on to the black top.

Interested in buying a Mitsubishi Triton? Get in touch with one of CarExpert’s trusted dealers here

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