The question about 4WD and how it assists with Hydroplaning has been asked many times over and this article will discuss exactly that. We will answer if a 4WD and AWD actually help prevent hydroplaning and which one is actually better in the wet. We will also explain what hydroplaning actually is, determine how it occurs and understand how to prevent it from happening to us.
Does 4 Wheel drive help with hydroplaning? 4 wheel drive assists the driver to control the vehicle in a hydroplaning situation since all four wheels have traction. With a 4WD vehicle more power will be sent to the slipping wheels when traction is lost. 4 wheel drive cannot prevent hydroplaning from happening but is less likely to be affected due to its excessive weight caused by the heavy ladder frame chassis compared to a lighter (2WD) two-wheel-drive vehicle with a lighter curb weight and less traction.
So now we know that 4 wheel drive does not actually prevent hydroplaning, but it can be advantageous when that situation arises due to its sheer weight and size combined with its superior traction on all four wheels when compared to a two-wheel powered vehicle. Next, we will look at defining how hydroplaning actually works and when it’s bound to happen on a wet road. Also, we’ll look at the advantages a 4WD has on slippery surfaces as well as how the weight of a 4WD affects its handling on low traction wet roads.
4 Wheel Drive and Hydroplaning
There are two scenarios at play here with regards to 4 wheel drives, hydroplaning, and wet roads. On the one hand, the 4 wheel drive offers superior traction over a 2WD on a wet road surface, however, the flip side is, if the 4 wheel drive is non-permanent 4-wheel drive then you most likely won’t be driving with 4WD engaged on a high traction surface such as tarmac or concrete road, even if it is wet.
So for the purposes of this article, we will assume we are referring to a permanent 4-wheel drive SUV vs a 2WD (two-wheel drive) passenger vehicle. It’s still a bit of an unfair comparison since the two will handle completely differently even on a high-traction dry road such as a highway or dry pavement due to its vast differences in weight, size, and suspension setups. But for the purposes of this comparison, let’s remove all the variables and look at it purely from a 4WD drivetrain and how it handles hydroplaning on any wet surface.
Let’s continue, by determining the physics around hydroplaning.
How does Hydroplaning Work?
Hydroplaning happens when a layer of water separates the vehicle’s tires from the road surface. If the tire cannot dissipate or eject the water fast enough, and this can be due to tread pattern, tire wear, or speed at which the vehicle is traveling, the tire rubber fails to make contact with the road surface long enough, resulting in the driver losing control of the vehicle.
When this occurs the driver interaction is ineffectual since, at that moment when hydroplaning occurs, the vehicle will be gliding or sliding across the road surface as if it were on sleek ice. No amount of braking or turning will affect the vehicle’s behavior until traction is regained. Driving a 4 wheel drive will be irrelevant at this stage.
The vehicle will simply continue traveling in the direction it was pointed at the time of hydroplaning occurring and the inertia will simply carry the 4-Wheel drive in that direction until traction is regained or until the vehicle comes to a stop. The hydroplaning effect could only happen for a few seconds but that could prove long enough to send you either careering off the road into a barrier or spinning into the opposite lane.
Now before hydroplaning can happen, the conditions need to be ideal. The 4WD needs to be traveling at 50 mph or (22.35 meters per second) and the water depth must at least be one-tenth of an inch (0.3 centimeters) to create the perfect hydroplaning environment. If the water is collected on a bend it’s even easier for this phenomenon to occur.
This is why most highways and concrete roads are built at a slight gradient, to allow water to drain off the road, prevent water from collecting, and minimize the risk of hydroplaning.
So next let’s look if a 4 wheel drive has an advantage in the above-mentioned scenario over a 2 wheel drive vehicle.
Does a 4WD have an advantage?
As stated from the outset, a 4 wheel drive is not immune to the effects of hydroplaning, however, it does have a two slight advantages over a 2 wheel driven derivative. Those two advantages are traction and weight.
Let’s look at each advantage in more detail.
4 Wheel Drive Traction vs Hydroplaning
Traction is explained as friction that builds up between the rubber of the wheel and the surface it’s traveling on. Lack of friction results in a lack of rolling traction. A four-wheel drive has 4 wheels that are generating friction and forward motion evenly over the surface thus resulting in improved traction around bends and on pull-off.
So when you are driving with a 4 wheel drive on a wet road covered in a layer of water, there are four wheels generating the friction and rolling traction, making it more difficult to lose traction. If you drive over a layer of water that is ideal for hydroplaning, a 4 wheel drive will need to lose grip and traction on all 4 wheels at the exact same time, in order for hydroplaning to happen.
A two-wheel drive only needs to lose traction on two of the wheels since the other two wheels are simply coasting along and provide no forward momentum.
4WD’s Weight affect and Hydroplaning
The depth of the water plays a major part when hydroplaning occurs. As mentioned in the beginning, you need to be traveling at 50 mph or (22.35 meters per second) and the water depth must a minimum depth of one-tenth of an inch (0.3 centimeters) to create the textbook hydroplaning condition. So the most important aspect that causes hydroplaning is the depth of the water combined with the speed at which you are traveling.
The weight of the vehicle and the rate at which the water can be displaced are all factors that contribute to hydroplaning. With that being said, a 4 wheel drive has a slight advantage in this scenario since the weight of the vehicle is heavier than a 2 wheel drive. This is due to the fact that most 4 wheel drives have bigger, wider tires for off-road conditions, as well as being a heavier-built vehicle. This is as a result of the ladder frame chassis, transmission box, extra differential, and the additional drivetrain components. All the additional components add extra weight to a 4 wheel drive total curb weight, making it a heavier vehicle and less prone to hydroplaning.
The size and width of the tires also play a critical role, since a narrower tire is more likely to cause hydroplaning over a wider tire. This is due to the lack of surface area that makes contact with the ground resulting in less traction. Most four-wheel drives have wide, aggressive AT (All-Terrain) tires which are designed to displace water and mud efficiently. Highway tires, which are commonly found on 2 wheel drive cars are designed for grip, comfort, and mileage.
Speed vs Hydroplaning
So now we know that weight, tire tread pattern, vehicle weight, water depth, and speed are all contributing factors to hydroplaning. However, the most important of all those have to be speed. Even If you are driving a vehicle with worn tires, (I’m not condoning, the act, simply drawing a comparison) you can still avoid hydroplaning if you drastically reduce your speed. The same cannot be said about the other factors since speed drastically increases your chances of hydroplaning on a wet road.
Then there’s always the common-sense factor and being extra alert on a wet road with dangerous driving conditions. These can include but are not limited to:
|Speed||Decrease your speed|
|Don’t make any sudden jerky |
|Scan the road ahead|
|Lose concentration||Pay close attention to any sudden |
slowing down of traffic
|Tailgate||Increase your following distance|
|Lose focus on the road and how |
other vehicles are reacting.
|Be alert for vehicles driving |
through puddles, throwing up
masses of water in front of you,
thus creating a hydroplaning
|Aggressive braking||Allow yourself a longer stopping |
time and distance
|Delayed braking||Begin braking earlier than usual|
The above-mentioned factors can all aid you to become a safer driver and avoid any unnecessary accidents when roads are wet and visibility is limited.
Next, let us look at how you should react when your vehicle starts hydroplaning. The dos and don’ts.
What to do When Hydroplaning
The first thing you should do when you are faced with this situation is to remain calm. The natural reaction would be to break or yank the steering wheel, but these will only aggravate the situation. Hydroplaning always catches unsuspecting drivers unawares, so your best bet is to be vigilant and on the lookout for dangerous sections in the read ahead of you. Prevention is better than cure, so expect the unexpected.
So let’s assume you are following all the above advice and your vehicle still manages to hydroplane, what action should you take?
Your first reaction would be to apply the brakes, however, this is the last thing you should do. You want to ease off the gas pedal to allow the tires to grip “naturally” again. Braking will aggravate the skidding and only send you careering into the nearest barrier, ditch, or worse. Braking aggressively will only result in the vehicle spinning completely out of control.
Gradually turn the steering wheel into the direction you are skidding towards, sort of like a counter-steer. This will allow your front tires to regain traction easier and it will regain the balance of the vehicle, avoiding a potential roll-over. This is especially true for 4 wheel drives with a high center of gravity caused by their high floor plan and ladder frame chassis.
Remain calm and allow the skidding to end on its own. Remember this happens in a matter of seconds so you only have one chance to react properly and it might seem counter-intuitive to turn in the direction of the skid, but that’s the quickest way to regain control of the vehicle. Think of rally drivers taking corners at high speed on slippery gravel roads. Notice how they adjust the direction of the vehicle by counter-steering. This is especially true for rear-wheel drive vehicles or AWD’s where the rear wheels get the majority of power, causing the rear end to fish-tale once traction is lost.
Overconfident 4WD Drivers
Many instances of accidents happening in wet driving conditions are caused by overconfident drivers and lack of awareness. Most people use common sense when driving on wet roads by reducing their speed and maintaining a safe following distance, however, there is always that one character that feels he is immune to the laws of physics because he drives an AWD or a 4 Wheel Drive.
Yes, a 4 Wheel drive can give you a sense of confidence that could prove false in certain situations, which could result in a serious accident or worse. If you driving a 4 wheel drive and you notice the traffic slowing down due to inclement weather, stay in your lane and follow suit. Remember, we all need to be careful and mindful of road conditions and other drivers who have different driving styles.
Driving on wet roads affects everyone, no matter what make or model vehicle you drive. Hydroplaning affects 2 4 wheel drives as well as 2 wheel drive vehicles. There are certain factors that decrease the chances of hydroplaning with a 4 wheel drive such as vehicle weight, tires, speed, and traction. These can play in your favor, however, you are still susceptible to the effects of hydroplaning.
Your best option is to become more aware and alert on wet roads. Adjust your driving style, decrease your speed and increase your following distance. Regularly inspect your tires for tread thickness and uneven wear. Remain calm and do not stomp on the brakes in the event of hydroplaning. Use common sense.