If you drive a vehicle that has a 4 wheel drive system and you driving in a part of the world that experiences heavy blizzards and snowstorms then you probably (heck yes) want to engage 4 wheel drive in those conditions. 4 wheel drive systems are designed to offer superior traction and control on low traction surfaces and ice roads qualify as such. If you would like to learn more about the advantages of driving a 4 wheel drive on ice then continue reading.
Should you use 4 wheel drive on ice? 4 wheel drive should be engaged as soon as you start losing traction on the road surface. 4 wheel drive systems send power to all 4 wheels aiding in maintaining traction while driving on slippery surfaces such as ice. 4 Wheel drive does not assist with braking or stopping on ice roads. Decrease your speed and increase your following distance. Winter tires with chains on a 4 wheel drive will offer improved traction on icy roads.
Now we’ve established that driving in a 4 wheel drive will not allow you to drive faster or brake later than vehicles with 2-wheel-drive drivetrains. The 4-wheel drive does, however, offer improved traction on slippery ice roads when pulling off and when cornering. You will still need to apply the rules of snow and ice driving even with a 4-wheel drive and you are not immune to the effects of slippery ice roads simply because you drive a 4 wheel drive. Next, let us look at how 4 wheel drive performs on ice and the advantages and disadvantages of winter tires as well as snow chains. Later we will cover the process to engage 4 wheel drive as well as how to use 4 wheel drive in snow.
Using 4 Wheel Drive on Ice
Driving on ice with a 4-wheel drive can be challenging even for the most experienced driver. You need to adjust your driving style accordingly and always be aware that traction can be lost at any time. Losing traction with any vehicle whether it’s 2WD or 4WD usually happens when you least expect it. Using common-sense is usually the best advice anyone can give you, meaning do not be reckless by speeding, cornering hard, braking harshly, and accelerating in corners when roads are slippery due to ice build-up.
The composition Ice changes throughout the day as the sun comes out and melts the ice and snow. Later it snows again on top of melted icy roads creating a slippery sheet between your tires and the ice below. The soft fluffy snow is the most treacherous especially when it collects on an ice-clad highway.
4WD safety on ice roads
So how does your 4 wheel drive contribute to your safety when roads become icy? Well, a 4 wheel drive provides traction on all 4 wheels. This means the rear wheels of your 4 wheel drive are constantly pushing while the front wheels are pulling. The traction of a 4WD is at its lowest point when you are cornering and braking so you want to decrease your speed when entering a corner by lifting off the gas slightly and easing into the corner. Do not accelerate harshly midway through a corner, even with a 4 wheel drive or AWD vehicle. With a 4 wheel drive all your wheels are constantly biting for traction and the friction between the surface and your tires is what creates and maintains grip. Once the grip is lost, that is when you could lose control of the vehicle and spin out.
4WD vs 2WD
A four-wheel drive has a massive advantage over a 2 wheel drive vehicle, either front or rear-wheel drive 2WD’s. With a 4-wheel drive, if you lose traction on 2 wheels you are still being powered by the other 2 which could prove advantages if driven correctly. It is always good practice to ease into a corner with a 4 wheel drive until you reach the apex of the corner and then proceed to gradually accelerate out of the bend. Never remove the vehicle from gear and coast through a corner since if you lose traction on any of the wheels you have very little control as to what the vehicle could do. A 4 wheel drive can understeer massively if you accelerate into a bend on an icy road which could cause you to hit an outside barrier or leave your lane.
Rear-wheel drives vs 4WD on Ice
With a rear-wheel-drive vehicle, for example, the power is only sent to the rear wheels and when driving on an icy road it is very easy to lose control by spinning out, especially if the vehicle is empty or un-laden, even in the case of a rear-wheeled Ute. This is because the rear wheels are constantly pushing the vehicle forward and rely heavily on the front wheels to maintain traction. If that happens, the vehicle will understeer heavily and could cause a crash. Because the rear wheels are powering the vehicle forward, if traction is lost on one or more of the rear wheels, the vehicle will begin drifting and if the vehicle has no traction aids like Traction Control or ESP, it could end up spinning out really quickly. It is only if the vehicle is in the hands of a professional or an extremely experienced rear-wheel driver, will the vehicle be able to be kept under control during an unintentional drift. This can be done by counter-steering and actually turning in the direction that the vehicle is sliding towards and lifting off the accelerator simultaneously to allow the rear wheels to bite again.
Front-Wheel Drive vs 4WD on Ice
A front-wheel-drive on the other hand always pulls the vehicle forward. This is slightly safer in a low traction icy road since the vehicle can maintain traction easier than a rear-wheel-drive vehicle. This is because the weight of the engine is directly above the front wheels which are powering the car. It’s a lot more difficult with all the weight above the wheels being powered to lose traction. In the event that the wheel does lose traction, it can simply be pulled back in line as long as the driver remains calm and remembers not to lift off the accelerator. The vehicle will simply pull itself straight if you keep the wheels in the right direction, which is the direction you want to be going. No counter-steering is necessary as in the case of a rear-wheel-drive car.
4 Wheel Drive on Ice vs Snow
Driving on a snow-filled road vs an icy road is very different. Thick snow causes a lot of resistance to forwarding movement whereas icy roads become slick and slippery, making forward movement challenging, especially when the ice and snow start melting.
When driving on snow you want to engage 4H immediately and when the going gets really rough, engage 4-Lo for slow, controlled driving at speeds below 10mph. This is more applicable when driving off-road, perhaps on a dirt road, grass, or a combination of the two.
Snow driving requires you to maintain a steady momentum and to pay close attention to when the wheels lose traction and start digging in. This is when you need to tap off the accelerator immediately since you run the risk of digging yourself into a deep hole flat onto the belly of the vehicle.
Snow driving can be different in the morning versus the evening since the texture and thickness of snow can change within a short space of time. When the snow melts and it snows on top of melted snow, is when things get really interesting. You need to be able to read the snow conditions well, and based on that, it will determine how you approach the snow. There will be scenarios where you will need to really use momentum to get through the really thick snow and other times you can get away with less aggressive driving.
When driving up slippery inclines you need to use a fair amount of momentum, as much as necessary, and choose the driving line correctly. You might not make the incline of a slippery path with your first attempt, which means you will have to retry and choose a better line. You might even need to engage 4-Lo and use your differential lockers to get up a slippery hill. In order to become proficient in snow driving, you need to really know your 4 wheel drive well. Know when the 4WD power starts tapering off and when to shift up or down.
Below is an extract from the article titled: How to 4 Wheel drive snow: pro tips
Learn To Read Snow When Wheeling
Understanding snow layers and the dynamic of snow can help you make smart decisions while wheeling. Weather patterns are constantly changing and snow will behave differently from season to season. Keep up to date with weather forecasts and check for updates regularly. Understanding these varied consistencies like the difference between soft wet snow in the sun from hard cold snow in the shadows of trees can prove valuable when out wheeling.extract from article titled: How to 4 Wheel drive snow: pro tips
From the top it all snow pretty much looks the same, however, it’s below the surface where things are constantly changing. The easiest method to determine what kind of snow you are dealing with is to make a snowball. If the snowpacks and sticks together, it’s going to be easy enough to glide over the top without digging in. Soft powdery loose snow will require you to drive through it instead of gliding over.
Stud Tires vs 4 Wheel Drive
When the heavy snow season arrives, even the most experienced drivers can find it challenging. Having the correct tires fitted are more important than a 4-wheel drive. If you have a 4-wheel drive and you have winter tires, that’s a bonus and probably the best scenario. But how do we know what the best tires would be to fit our 4-wheel drive?
Well, that will depend largely on the kind of weather and road conditions you are faced with. If you are in a country that gets icy road conditions regularly throughout the winter season, then a studded tire will be your best option. These offer the best traction on ice-clad roads since the metal studs dig into the ice to provide traction.
The only disadvantage with the stud tires is that they should never be driven on dry roads when traction is good. The studs cause massive damage extending into the millions of dollars every year for repairs to roadways. They are strictly meant for icy roads and should be removed and refitted as needed.
Driving with stud tires on a two-wheel-drive vehicle can even prove to be effective in the snow. Only the wheels that are propelling the vehicle i.e rear wheels or front wheels should be fitted with stud tires.
How to engaging 4 Wheel Drive
4 wheel drive is designed to be engaged as soon as you leave the tarmac and traction becomes limited. If you have the functionality, use it, that is what you purchased the 4 wheel drive for. When traction is limited, safety and handling are compromised so do yourself and others a favor and slow down to below 60mph and make sure you are in neutral to select 4H. If you have a 4 wheel drive equipped with 4WD Auto functionality, simply select the 4A at speeds under 60mph and proceed as normal. The sophisticated computerized 4WD system will sense when traction is lost and take care of business for you without any guesswork.
A non-permanent 4 wheel drive will require the driver to constantly survey the driving surface to ensure the traction is always limited or slippery enough to warrant 4WD 4H and make sure the roads have enough slip to avoid drivetrain binding.
The drivetrain binding effect occurs when the traction is not low enough to allow the front wheels to rotate at a different speed to the rear wheels, especially when turning. The torque generated by the engine will be transferred back into the transmission and transfer case and cause massive damage. Damage to drive-shafts, transfer cases, u-joints, transmission gears and more could result in driving in 4H on dry pavement or highway with good traction. The extent of damage will depend on how long you’ve driven in 4H.
4-Hi or 4Lo in Ice and Snow
When driving on ice with a 4-wheel drive you want to immediately engage 4H. If you have a 4 wheel drive with the 4A (4Wheel drive Auto) function, rather select 4H instead of 4A. The reason for this is when the vehicle is in 4A mode, it first needs to lose traction before it engages the front wheels to convert the drivetrain to 4H. Even though this happens within seconds it could mean valuable time when driving under treacherous conditions. 4H means all the wheels are constantly being powered and traction is at its best.
On the contrary, if the road surface is a mixture of high traction and slippery areas, then 4A will come into its own. Here you engage the 4A and let the computer and sensors determine when to engage 4H automatically. This will prevent drivetrain binding while offering you the added benefit of decent fuel consumption on the high traction areas.
4Lo should only be engaged when not driving on any roadways and when traction is at its lowest where you need to exercise the most caution. Do not engage 4Lo on the highway or any roadway. 4Lo is designed for serious, challenging low traction environments. Engage your lockers only when absolutely necessary to overcome serious obstacles.
So to recap, should you use 4 wheel drive on ice? The answer is a definitive yes. 4WD offers improved traction and pull-offs, however, it offers little if anything for braking. Engage your 4-wheel drive as soon as driving conditions become slippery or immediately when you leave the tarmac. 4-wheel drive with winter tires will be very advantageous, offering maximum grip when roads become slippery and covered in ice or snow.