Four-wheel drive (4WD) vehicles have come a long way. It wasn’t so long ago that they were used almost exclusively to navigate rugged off-road terrain. But now these vehicles are more fuel-efficient, practical, and popular than ever. And while more drivers have an interest in 4WD, there remains considerable confusion in the marketplace. Our Comprehensive Guide to the 4-Wheel Drive is designed to answer your questions and, in layman’s terms, help get you up to speed about the evolution of this exciting technology. This guide to 4-Wheel Drive will cover the following topics:

• What is 4 Wheel Drive?
• Full-Time 4-Wheel Drive vs Part-time 4-Wheel Drive
• When to use 4 Wheel Drive Low (4Lo)
• When to use 4 Wheel Drive High (4Hi)
• Advantages & Disadvantages of 4WD
• All Wheel Drive vs 4 Wheel Drive: What is right for you?

What is 4 Wheel Drive?

At its most basic level, 4WD is a vehicle transmission system that provides power to all four wheels of a vehicle at the same time. In order to answer the question, “What is 4 wheel drive,” we must differentiate between part-time and full-time systems.

Full-Time 4 Wheel Drive

The original 4-Wheel Drive dates back almost a century, and today it is known as the “full-time,” or permanent, 4-Wheel Drive, and is used almost exclusively by serious off-roaders. It is strong, heavy, and durable in inclement weather, but its sturdiness comes at the expense of fuel efficiency and handling. Its drivetrain configuration distributes power to all four wheels simultaneously, regardless of the driver’s need or terrain’s uniqueness.

Part-time 4 Wheel Drive

To address the full-time 4WD’s drawbacks and to market it to a broader audience of drivers, manufacturers came up with the part-time 4WD systems. One difference is that part-time 4WD vehicles stay in rear-wheel-drive configuration until more traction is required. Instead of sending engine power equally to all four wheels, this version can efficiently distribute the torque to the wheels that need it the most. This has the effect of decreasing the amount of drag on the driveline and creates better efficiencies as well a modest improvement in gas mileage. In addition, part-time 4WD vehicles require the driver to switch a lever manually in order to transition from a 2- to 4-wheel drive. Also, the 4-wheel power cannot be engaged on dry pavement without causing serious damage to the engine. The part-time system shares something in common with the full-time 4WD: it has the same low gear and locking apparatus as the traditional 4WD system. What is 4 Wheel Drive? It means different things to different people. For the purposes of this blog-post, unless otherwise specified, we will be referring to part-time 4WD as opposed to the full-time or permanent 4WD. Many 4WD systems also have low and high ranges that can be selected by the driver, either with an electronic switch or a floor-mounted mechanical lever. The low setting provides maximum traction in an off-road environment, while the high setting is the default configuration, useful for slippery on-road conditions, such as packed snow, ice, loose sand or gravel.

When to use 4 Wheel Drive Low (4Lo)?

The 4 means your vehicle is in 4-wheel drive mode and all four wheels are being used, while the Lo refers to low-range. A driver might want to shift to 4Lo mode if he encounters a difficult section, like a tall sand dune or a deep river crossing, and needs optimal power and traction to avoid stalling. To engage and disengage 4Lo, make sure to stop the vehicle first before you switch the driving mode from or back to 4Hi or 2Hi.

How and When to use 4 Wheel Drive High (4Hi)

A 4WD is not appropriate for all driving conditions. Knowing when and where to use a 4WD is important for safety reasons so you don’t damage your vehicle. It’s time to become familiar with driving surfaces since road conditions and terrains are mostly what determine what gears to use. When to use 4 Wheel Drive High? A part-time four-wheel drive should be placed in 4Hi mode as soon as the driving surface becomes slippery or wheel traction is low. Unlike full-time 4WD vehicles, modern part-time 4WDs do not require you to stop the car or slow down before switching from 2Hi to 4Hi. Simply shift the lever to 4Hi, which will distribute power to your front and rear axles.

How to navigate steep descents

Navigating steep descents is best done slowly and carefully. Getting out of a hairy situation requires better traction and more control, and that means it is one of those infrequent occasions that you will need to engage 4Lo and your lockers.

How to drive on gravel roads

To navigate gravel roads, tire pressure and speed are key factors. To prepare for it, start by reducing the air pressure in your tires to 1.5bar and maintain a safe speed. If your vehicle is vibrating excessively, reduce your speed even more. Keep your eyes fastened on the road ahead so you can anticipate and avoid potholes and craters.

How to disengage 4WD mode

Suppose you are driving in 4Hi on a wet road, and you turn onto a drier surface with better traction. At that point, you may shift back to 2Hi, which is achieved by first fully stopping your vehicle and then moving the gear lever back to 2Hi.

Here are some scenarios where you should avoid using 4Hi:

• On the highway if it’s not raining or snowing
• On cement if the conditions are dry
• On winding roads that are not otherwise slippery
• On any driving surface with good traction and driving conditions

Say, for example, that you are going for an off-road trip. For the initial section on the highway, before you get into the country, there’s no need to engage 4Hi. Using 2Hi will give you a nice ride with better gas mileage. Once you approach new terrain, like ice, snow, gravel or asphalt, engage 4Hi immediately.

Advantages

The main advantages is the off road superiority of a 4WD and its ability to take you places that smaller cars cannot go. Whatever terrain you have in mind – gravel, rocks, sand dunes, mud, hills, ice, or snow – a ladder frame 4WD is up to the challenge. A 4WD provides enhanced traction and better control in dangerous driving conditions. And for those who enjoy the off-road experience, a 4WD delivers plenty of fun and thrills.   

Disadvantages

While a 4WD carries many benefits, it is also important to recognize its disadvantages. While 4WD may help with acceleration, it does not make it easier to stop or turn on low traction surfaces. If you are concerned about that, invest in some all-terrain tires. Also, some drivers are not thrilled with the way a 4WD handles, relative to smaller cars that they are accustomed to. In some situations, because of the higher center of gravity, a 4WD can feel less stable and may be more prone to body roll, such that, when navigating a sharp corner, your body leans toward the other direction. Finally, a 4WD’s mass makes it harder to brake and its larger turning radius can make it difficult to turn and park. The weight of its frame causes it to consume more gas compared with smaller cars, so you will pay more to fill up the tank.

What is all-wheel drive?

All-wheel-drive is a system that distributes power to all four wheels continuously, whereas part-time AWD usually drives in two-wheel-drive mode unless and then, as road conditions necessitate, provides power to all four wheels. You will commonly find car-based SUVs and minivans sold with AWD. A feature of AWD systems is that the driver doesn’t need to manually shift into a different mode; the system does it automatically when its sensors indicate the presence of snow or a gravel surface. As we previously mentioned, most 4WD systems come with high and a low gear range and differentials, which gives the driver better traction on a slippery surface. In an AWD, there is no high and low gear range, which can be an advantage if you’re seeking simplicity or a disadvantage if you’re an off-road aficionado.

All wheel drive vs four wheel drive

What system is right for you? It depends on the individual. As you compare all wheel drive vs 4 wheel drive, you will need to weight various factors, including how you will use your vehicle, your regional location (and weather), and your personal taste. AWD vehicles can hold their own in moderate mud, sand, and snow scenarios. However, off-road drivers tend to prefer traditional 4-wheel-drive vehicles, because of their superior performance in rugged terrain and their maximum pulling power. To summarize: In this particular guide, we addressed several topics, including what is 4 wheel drive, what are the differences between part-time and full-time 4WD, and when to use 4 Wheel Drive Low and when to use 4 Wheel Drive High. We also walked through the advantages and disadvantages of 4WD and compared all wheel drive vs 4 wheel drive Four-wheel-drive vehicles are changing and becoming leaner, meaner machines. But they haven’t lost any of their toughness and are still loads of fun to drive. Understanding how to work the gear selection and when to engage 4Lo takes a little getting used to, but the rewards are hard to argue with: Getting off the beaten path, enjoying the natural landscape, and savoring the off-road experience and adrenaline rush that only a 4 X 4 can provide.   This blog post was contributed by Fix Auto Coeur d'Alene a leading industry expert and collision repair shop servicing the Kootenai County as well as neighborhoods between Coeur d’Alene and Spokane, Washington.