Your 4×4 is an open ticket to a never-before-experienced world of off-road adventures. It has the bush-ready set-up (purpose-built engine and drivetrain with dual-range – high- and low-range – transfer case, suspension and more) aimed at getting you to places those with a two-wheel-drive (2WD) or all-wheel drive (AWD) vehicle can only ever dream of.
The problem is there are plenty of 4×4 (four-wheel drive) owners who have never used low-range, or even know when they should use low range, or indeed how to engage four-wheel drive at all.
There’s no shame in that, and it’s easy enough to get your head around the proper operation of it all once you have – that’s why we’re here.
If you live in an area where there is a lot of snowy and icy weather, four-wheel drive is an important feature to help you get where you want to go. Most four-wheel-drive vehicles are equipped with a four-high and a four-low function.
Auto Solutions in Maryville, TN wants to provide some tips on when 4H and 4L should be used. You can use 4H when you are driving at a normal rate of speed. If you are driving on the highway and the snow is falling using 4H is the way to go.
You can also use 4H when you are driving on sandy and rocky roads where you need better traction.
You should only use 4L when travelling under 40mph. 4L routes significant torque to the wheels to get you out of really tricky situations such as deep snow and mud. Going too fast in 4L can damage your vehicle, so be cautious.
For most vehicles, you have to be stopped and in ‘park’ to shift into four-wheel drive. If you are driving at high speeds, you can use 4H to give you better traction on the highway during snowy or rainy conditions.
4L should be used for extreme off-road conditions and at slow speeds. It’s also important to not go too fast when in FWD; a good rule of thumb is not to exceed 55 mph in 4H and don’t go faster than 35 mph when you are in 4L.
What Are The Different 4wd Modes?
If you are new to 4WD vehicles, it can be quite intimidating trying to understand all the different types of lingo and acronyms.
For starters, 4WD (four-wheel drive) refers to a vehicle that has the capability to provide power to all four of its wheels at the same time. Many modern vehicles have the capability to change modes with a simple flick of a switch.
However, 4WD vehicles come with an array of features and modes that all have specific uses.
Engaging these modes at the incorrect times could lead to long-term damage to your vehicle make sure you read our article on accidentally driving in 4WD if it happens and what to do. With that in mind, you must understand what each mode is what their intended uses are.
High Range (Four High, 4h)
High range mode, commonly depicted as 4H, is best implemented when you are travelling at normal speeds but the terrain has harsher conditions.
Drivers will commonly switch to this mode when they are on highways with less than optimal conditions. Examples would include dirt or gravel roads, wet and icy roads.
4H is used for normal-speed driving, but for when you need extra traction to rotate all the wheels.
These situations might include muddy roads, ice or snow-covered roads, or hard-packed sand.
At that engage your lever or make sure you’re in the 4H mode it will engage your both front and rear wheels in high-range, using the same gear ratio as of the 2H for normal driving speeds.
The front wheels come in traction, making the vehicle more stable on loose surfaces and not to stuck in the obstacle.
Due to the purpose of this mode of your vehicle, it won’t bring any excess damage to your vehicle if you drive safely while engaged in this mode as long as you maintain normal driving speeds.
Low Range (Four Low, 4l)
While 4H is recommended for higher speeds, low range or 4L is most effective when you are travelling slower over non-road terrain.
If you were to attempt to traverse over water, mud, snow or sand, this mode is the preferred choice. As we previously mentioned, this mode of your vehicle engages your wheels with more torque, so it is most effective when you are travelling at low speeds.
Combining 4L along with a reduction in tyre pressure will allow you to traverse over some of the harshest terrains.
4L is used when you need more torque but less speed, i.e. it provides max torque and max power.
It is used in conditions like sharp inclination and declines, deep muds, rocky surfaces, the 4L mode makes the vehicle to crawl in slow speed. Front and rear wheels are driven in low range speeds.
All four wheels turn much more slowly per revolution than that of they would result in high-range, it results in slower road speed but gives higher torque basically, it multiplies the torque to 3times, it is according to manufacturers the 4L ratio of Mahindra Thar is 3.73: 1, means it will give the torque output of 600N-m with 4L mode, which assists the vehicle on inclination and declination, the lower gearing ratios gives the vehicle engine braking, making it easier to control on the descent.
What Is 2h?
2H is used for normal road driving conditions where you expect more fuel efficiency from your vehicle. In this mode, two wheels are driven.
Usually the rear or front it is according to the manufacturer, the H=high-range means the normal gear ratios are used for everyday driving. In an exceptional case, Some vehicles may be constant 4WD or all-wheel drive, in which case they won’t have the 2H option, but in India, it’s not available because of the reason fuel efficiency.
How 4wd Works
According to How Stuff Works, there are a variety of four-wheel-drive systems. Most of the time, however, when an automaker says a truck has 4WD, this means that it is a part-time system. Vehicles with all-wheel-drive can sometimes be called full-time 4WD.
But no matter your drivetrain, it all works the same. Your truck has two differentials (one between the front wheels and one between the rear), which sends torque and power from its transmission to the drive wheels.
Sending this power can allow for better use of traction in different situations. Your 4WD setting determines which tires and parts of the truck are receiving the most power. And each 4WD setting has its purpose and advantages.
Most older 4WD must be manually switched between transfer cases, while new 4WD systems have electronic settings that allow you to shift while driving.
While an AWD vehicle can send all of its power to all wheels at the same time, 4WD allows you to choose where your truck will receive its power. The goal of 4WD, as quoted by the folks at McNeill Nissan, “is to get more traction when traction is hard to come by.”
High- And Low-range Explained (Basically)
If you want a detailed explanation of a 4×4 system, go here but for this yarn, remember these few basic points for those of us with an off-roader armed with a dual-range transfer case:
In 2H (two-wheel drive, high range) two wheels, usually the rear, are driving your vehicle. You use 2H for normal road driving.
In 4H (four-wheel drive, high range), all four wheels are driving your vehicle. You use 4H for surfaces on which you may need greater traction than you would for bitumen; think firm sand, dirt roads, gravel tracks and the like.
In 4L (four-wheel drive, low range), all four wheels are driving your vehicle, and a low gear ratio is being used.
Your vehicle’s wheels will turn much more slowly than they would in the high range, so slower speeds and more torque are the go. You use 4L for soft sand, dunes, steep hills and declines, deep mud or snow, and slow-going rock-crawling.
It used to be that you would have to engage high- or low-range using a little shifter near your main manual or auto shifter.
Some of us from The Old Days even had to get out of our 4x4s and actually lock our manual locking hubs on the front wheels for off-road work, and then unlock them when switching back to 2H. Not any more; you can now switch to high- or low-range via a dial or knob in the cabin.
In many modern 4x4s you can switch from 2H to 4H without stopping, but still have to come to a complete stop to switch from 4H to 4L.
When To Use Low Range
Use 4L when you need optimum traction and absolute maximum power. As we said before, in 4L (four-wheel drive, low range), all four wheels are driving your vehicle, and a low gear ratio is being used.
Low-range is one of the keys to the kingdoms of beach and bush. You’ll use the low range to get you through soft sand, over soft-sand dunes, up steep hills and declines, through deep mud or snow, and it’ll help you drive over rocks.
The lower gearing also gives your 4×4 vehicle better engine braking, which helps to control your progress on downhill sections.
How To Engage Low Range
Before you switch to low range, deflate all of your tyres to a psi (pounds per square inch) pressure that suits the terrain. As we always say: get your tyre pressure right, and that goes a long way to getting you across, over or through pretty much any natural challenge.
Aim for tyre pressure between 15 and 18psi for soft sand and soft-sand dunes, although you may have to go lower. Use between 20 and 25psi for mud or rocks, but again, you may have to drop pressure even lower.
To engage low range, stop your 4×4, put it into Neutral or Park, and use your dial to switch from either 2H to 4L, or (assuming you’ve been in 4H in the lead-up to the low-range terrain you’re about to tackle) 4H to 4L.
Watch for an illuminated icon or lettering (‘4L’) on your instrument panel to indicate that 4Low has been engaged. Don’t drive up the hill or onto the terrain you’ve selected 4L for until you are certain low-range is properly engaged.
Once you know 4L is engaged, shift into first gear, ease your foot off the brake and allow the vehicle to crawl up the hill, across the soft sand – whatever you’re on.
In low range, let your vehicle do the work; use gentle acceleration, soft braking and, here’s the secret, go slowly. Change up or down through the gears as required. Take your time and creep along.
You don’t need to do a whole lot more other than watch your wheel placement, check for hazards and enjoy the ride.
The Difference Between 4hi, 4lo, And 2hi: When To Use Each
Every 4WD vehicle comes with multiple modes or gears that your truck can be switched to. Each gear has its job and its purpose, controlling your truck’s differential and where it sends its power. Here are the settings you can use with a 4WD truck and how to use them:
2Hi: 2Hi can also simply be referred to as two-wheel-drive, and it’s the most commonly used option. In two-wheel-drive, your truck’s system delivers all of its torque to the rear differential, allowing each rear wheel to receive half of the available power.
Once switched into 4WD, each tire will receive a quarter of that power. This is what you would use for daily driving, on dry conditions, at normal speed. For people with automatic 4WD or AWD with automatic 4WD, it can be switched automatically from 2WD to 4WD when it senses slip in the wheels.
4Lo: When in 4Lo, your truck is sending torque to all four wheels, but in the low range. 4Lo is best used on slippery surfaces.
This can mean rain, sand, or even mud. While in 4Lo, your truck doesn’t get as much traction, but way more torque.
4Lo is also best used while driving at slower speeds (under 40 mph) and should be used if you need to “crawl” through a slippery surface. It’s also beneficial when you need more power for pulling heavy loads at slower speeds or climbing steep grades.
4Hi: 4Hi is best used at regular or highway speeds (at least over 15 mph) when you need tons of traction and less power.
It’s best used in snow, ice, very slippery conditions, mud, and more. 4Hi is good for level roads, with minimal grades.
In 4Hi, your front and rear differentials lock together, creating the ultimate traction. According to Popular Mechanics, because it does not offer the same push of torque as 4Lo, 4Hi is best for getting through a situation, not out of one.
Automatic Four Wheel Drive (Awd)
If you have just begun your 4WD experience, it is recommended that you utilise this setting. AWD is a function that detects the conditions of the road along with the torque of your wheels and will change the driving setting automatically.
For example, if you were driving down a highway, and it starts raining, the vehicle will analyse the change in road conditions and change into the 4H mode.
Prolonged use of some modes in the wrong conditions can damage your vehicle, so AWD is great if you’re not experienced with 4WD vehicles as it does the thinking for you and will turn off the settings if you are using them wrong.
What Not To Do When In Low Range Mode
As mentioned previously, each 4WD mode has an intended use and utilising these functions at the wrong time can damage your vehicle.
Low range mode is intended for slow driving across harsh terrains. It is not meant for high speeds and can damage your vehicle. It is highly recommended that you don’t exceed 60 km/h when you are engaged in this mode.
Driving for long periods of time at high speeds can do some serious damage to your vehicle. If you accidentally have engaged 4L while driving at high speeds it is highly recommended that you take it into the shop.
Bearings and axel belts can wear down extra quick when this mode is used like this, so it’s always better to be safe than sorry.
When you are finished driving in 4L mode, it is important that you re-inflate your tyres to their correct pressure and engage the right mode for the surface that you are on.
If you’re going back onto pavement or bitumen, switch it back to 2H otherwise for the firm and go to 4H.
Another important thing to note when you are four-wheel driving is that you shouldn’t be taking any sharp turns. This is included for both high and low range modes at can also seriously damage your vehicle.
When you engage 4WD, the front wheels are locked into place and can cause your vehicle to slide and jerk. With the build-up of torque in your vehicle, it is possible that your vehicle can flip if you take a sharp enough turn.
This happens due to the build-up of torque becoming so high that it needs to displace the extra force.
*Important Things To Note About 4wd Modes
One of the most important things to remember about 4WD systems is always to use each 4WD setting properly.
According to Allstate Insurance, “you should never travel in four-wheel drive on flat, smooth, dry roads, as it will damage your drivetrain.” It shouldn’t be used on smooth, flat, dry roads and it’s important to remember that the increased torque and traction do not mean you will stop quicker. You’ll still need to allow for ample braking time, especially in adverse conditions.
Before you engage any 4WD mode, it is important to remember that your vehicle is providing more torque to your wheels, but it doesn’t help you stop.
Braking can be difficult, so you must remain at speeds that allow you to brake. Regardless of your driving conditions or experience, safety is the most important part of any 4WD trip.
You may also be wondering when it is okay to shift modes when you are driving. The answer is that you should come to a stop when going in and out of 4L mode but other mode switches are fine. If you are travelling down a highway or on a dirt road, it is completely fine to transition to and from 4H to 2H while you are moving. You can always check what mode you are in by looking for the light-up indications on your dash.