Invented over a century ago, the four-wheel drive system (4WD) has brought convenience and a feeling of security to modern driving. Because of this breakthrough, sportier on-road pursuits are no longer limited to the skilled few who can overcome obstacles riding a 2WD vehicle.
Beginner and more advanced drivers can now take advantage of driveline modes that make traction and vehicle control as elementary as learning ABCs. But with the slew of options available, which one is appropriate to use? Is it 4WD High or Low? And how are they different?
Each driveline mode specializes in specific low-traction applications though they share power transmission and working principles. Between 4WD High and Low, the former is typically utilized in daily driving. Meanwhile, the latter is geared more toward rough terrain and extreme riding conditions.
4WD may be a no-brainer for off-roading veterans and enthusiasts. But for everyone else, fully grasping these drive systems may be easier said than done.
This is why we need to study up on these driveline modes — so we can finally take the guesswork out of determining which works for which on-road scenario.
Different 4WD Modes
Not too long ago, we covered the differences between AWD and 4WD systems and cited scenarios where one is more appropriate to use (if not to outperform) over the other.
We will discuss something similar in today’s guide. But this time, we will focus on two different 4WD modes.
The Four-Wheel Drive System or FWD/4WD consists of five driveline modes: differential lock, 2H, 4H, 4L, and hill descent control. Depending on the year, make, and model, you may have all or some of these driveline modes included in your vehicle’s standard list of features.
For modern, sophisticated vehicles, these modes may be more and are operated via buttons, knobs, and electronic switches. For vintage traditional four-wheelers, operability may depend on a floor-mounted lever or 2nd gear shifter.
How these controls direct torque to your front and rear wheels (view on Amazon) may also be part-time or full-time.
4WD High, 4H, or 4-Hi
4WD High or 4-High is a driveline mode that uses regular transmission in splitting engine torque evenly between your car’s front and rear axles.
You can enable it at speeds of around 25—62 mph (40—100 km/h). However, you first need to be in gear before activating the mode via a push button, knob, switch, or whatever your 4×4 has.
Especially for experienced off-roaders, it is very unlikely to encounter cross-axle locking when engaging 4WD High (unless you manually activated the mode or are just beginning to understand your rig’s body English).
It is generally reliable in modulating torque across your axles. But situations will arise where you may have to employ the services of your rear differential for additional traction. Enthusiasts refer to this combo mode as 4WD Lock.
4WD Low, 4L, or 4-Lo
Functionally, 4WD Low or 4-Low is the opposite of the mode described above. And instead of making use of regular transmission, it enlists a low-range transfer case (view on Amazon) with tighter gear ratios (and mated to a gear or belt-driven system) to handle wheel spin relative to engine speeds. Plus, you have to be in neutral.
The transfer case’s tighter rev band allows the driver to regulate wheel speed in a more controlled manner while using engine braking. Torque surges are consequently reduced, and having to rely solely on mechanical brakes when navigating long, steep declines is eliminated.
Its caveat? You cannot engage this synchronously with stability control, traction control, or ABS. Nor should you do so at speeds beyond 37 mph (60 km/h).
What Is the Difference Between 4WD High and 4WD Low?
We have answered this question in part by defining the focal driveline modes. But in the event you find the above details insufficient, refer to the table below for further dissimilarities between 4WD High and 4WD Low concerning specific parameters:
4WD High vs Low Comparison
|Parameter||4WD High||4WD Low|
|Working Principle||Sends power to all wheels between the front and rear axles evenly||Sends power to all wheels between the front and rear axles evenly but with lower gearing|
|Power Transmission||Typically uses regular transmission and differentials to distribute power to the front and rear wheels.||It uses a transfer case to distribute power to the wheels|
|Power Delivery||Sends power to the wheels unless paired with locking differentials||Sends power to the wheels unless paired with off-road cruise control|
|Application||Fit for road-going vehicles used for daily commutes and high-performance cars needing superior handling and grip.||Suitable for sport/adventure driving or off-road vehicles driven in extreme off-road conditions with very low traction|
Pros and Cons
- An all-rounder feature perfect for urbanites
- Best at handling adverse conditions on-/off-road
- 4WD Auto modes have a center differential. Power and torque are distributed between the front and rear axles.
- Some manufacturers limit the drive system’s allowable speed to 55 mph (88.5 km/h)
- Well-suited for heavy-duty hauling, utility work, and difficult terrain
- It provides better pulling power than an All-Wheel Drive System
- It only applies to slow-moving, high-traction scenarios
- Frequent use in high-traction situations can be incredibly taxing on mechanical parts
Shared Benefits and Drawbacks
- Improves road grip during low-traction scenarios
- Well-suited for heavy-duty hauling, utility work, and difficult terrain
- Increases the base price of most vehicles
- It may not be suitable for 2WD aficionados
- Longer braking distance to stop the vehicle
- Incremental savings on fuel
- A mechanical feature —hence, driver input is required
- Adds to the heft and complexity of the drivetrain, making servicing difficult
- Can contribute to overconfidence
When to Use 4WD Low vs High
Between 4-Hi and 4-Lo, no drive system is inherently safer if comparing them flat out. That is because bringing out their ‘safety’ attribute is largely situational.
In slow-moving, extreme terrain conditions, 4WD Low gives better assurance. But in high-speed situations, 4WD High is the safer mode to use.
This is where your choice of vehicle becomes essential, as not all four-wheelers are equipped with a full quartet of driveline systems. The last thing you would want to happen is to drive all the way to Moab — only to put yourself in danger for not having the 4-Low feature to ease you out of those rock boulders and vertical climbs.
Unlike vintage, classic cars, modern SUVs and crossovers have more than one source for road grip. And when I say this, I do not mean driving skills or TCS (Traction Control System).
Especially for vehicles with 4WD Auto, on-tap traction is always there and engages automatically when needed. And in a way, this makes 4WD High well… somewhat redundant.
But ultimately, opting for 4WD High over 4WD Low (or vice-versa) hinges on the string of drive systems your car is equipped with. If your vehicle has 4WD Auto, there will be no need to engage 4WD High manually since all the latter does is “lock the front and rear end together.”
It is an entirely different story with 4WD Low, as you will find yourself in slow-crawling, boulder-crossing sections at one point or another.
Although the price tag of your vehicle may have a direct correlation to the complexity of its drive systems, it does not necessarily translate to having or not having high and low 4WD modes. If anything, the type of rig you drive has a more direct impact on the availability of certain driveline modes.
Case in point, 4WD Low seems to be found only in pickup trucks, crossovers, and SUVs recently. On the other hand, vehicles in the $40K range, like Toyota 4Runner and Jeep Grand Cherokee, have a complete 4WD system.
Should you fancy a car outside these makes and models, be prepared to shell out an extra $2,000–$4,000 on top of the base MSRP to have 4WD High and 4WD Low included.
Whether or not utilizing 4WD High or Low is necessary is contingent on the intended application, as is the case with riding conditions (more on this later). Ultimately, buyers choose a rig based on specific activities or hobbies they have in mind — on top of budget constraints and styling preferences.
A weekend warrior living in South California would most likely purchase a Jeep Wrangler 4WD for daily commuting, weekend beach travels, and the occasional outdoor adventures. Meanwhile, someone in the landscape business would probably go for a Ford F-150 with 4WD Low for its high payload rating and towing capabilities.
In the same post where I discussed AWD and 4WD systems, I mentioned that fuel economy gains for 4WD-equipped vehicles are fractional (if not negligible). The same principle applies to 4WD Lock vs 4WD Low or 4WD High vs Low.
Since both are four-wheel-drive systems, they naturally add weight to a vehicle. Albeit inadvertently, the extra weight is bound to add stress to the drivetrain and dampen the rig’s fuel efficiency in the long run.
Given this premise, choosing 4WD High over 4WD Low should never be based on improving fuel efficiency. In truth, opting for either driveline mode will have no positive impact on gas mileage, regardless of the size of your vehicle.
Instead, always base your choice of drive system on traction needs and driving speed.
Even for frequent off-roaders and overlanders, it takes time to fully grasp which driveline mode goes with which type of terrain. You simply cannot group riding conditions under 4-Hi or 4-Lo based on the need for (or lack of) torque multiplication.
Some riding conditions may pose similar challenges and traction requirements. However, various terrain types will cause your 4×4 to behave differently once in contact with your wheels.
When choosing 4WD High or Low for snow, pick the former. I know, 4WD Low may seem more sensible. However, there are a couple of irrefutable prerequisites when engaging 4-Lo — these are high traction at low speeds.
On slick surfaces like snow-laden roadways, what you need is low traction at relatively high speeds. And this is exactly what 4WD High offers.
In getting out of tricky situations like deep sand or mud, go with Low 4WD. This driveline mode also works best when climbing steep inclines or hauling heavy loads.
Just like in deep mud, these other scenarios require torque distribution to all four wheels to give you that much-needed oomph and get you out of a predicament.
Conversely, both 4WD High and Low are counter-intuitive to use on sealed roads as you are forcing your drive system to rotate wheels on a surface with insurmountable friction.
Climatic conditions almost always make a driver predisposed to choosing a particular driveline mode. Not to mention that weather can adversely impact traction control on the same type of terrain.
Inclement weather can turn off-road dents into shallow water crossings and dirt trails into muddy roads. And so, the need for 4WD High and 4WD Low in these situations also changes.
When driving on snowy paved roads, car owners are torn between using 4-Lo and 4-Hi. Some claim that 4WD Low is the mode to choose when going through extreme ice or snow.
Meanwhile, others insist on using 4WD High since torque multiplication has little effect on preventing hydroplaning on slick surfaces.
Last but not least in the slew of things to consider before using 4WD High or Low is driver skill. How adept you are on the road will dictate how frequently you employ either drive system (or if you need to use them at all!).
Of course, some circumstances warrant using one or the other — even if you prefer not to. But if it is just urban driving, traversing interstate routes, the occasional backroad tours, and the like, you may not have to rely on 4WD High or Low as often.
Road legends (your grandpa included) can attest to this. Those who learned how to drive 2WD vehicles find themselves only using 4-Hi or 4-Lo in dire situations.
Conversely, nouveau riders would have the opposite inclination — heavily relying on these driveline modes while they develop their on-road intuition.
Conclusion — 4WD High vs Low: What’s the Difference?
In summary, the main differentiator between 4WD High and 4WD Low lies in traction requirements and engine speed. Depending on several factors mentioned in this article, you can combine these driveline modes with locked differentials or engage them individually.
Road experience will teach you a great deal about how these systems work. However, those hands-on lessons work best with a working knowledge of your 4×4’s differentials, transfer case, gearbox, and couplings.
Understanding when to use 4WD High vs Low is merely the proverbial tip of the iceberg. Once you have mastered their uses well enough to do them on instinct, that is when the real off-roading fun starts.
By then, all you have to worry about is damage control — up-to-spec tire pressures, recovery points, undercarriage protection, and the whole shebang of pimping your rig for the outdoors.
Kris is an avid off-roader and outdoor enthusiast who loves to brave the elements and take on challenging terrain. He also enjoys sharing his passion and knowledge with others so that they, too, can appreciate the ride.