A situation where the rear axle of your car begins to be demolished to the side, and the trajectory of movement ceases to correspond to the steering wheel, always causes stress. This is a condition called skidThe behavior of the all-wheel drive car (AWD or 4WD) at this point is radically different from the classic rear or front-wheel drive. Unlike monodrive cars, where the algorithms of actions are clearly spelled out in traffic books, all-wheel drive requires a more nuanced understanding of the transmission.
The main feature is that the traction here is supplied to all four wheels, which creates the illusion of "all-terrain" and stability. However, when traction is lost, all-wheel drive can both save the situation by better acceleration and make it worse if the driver does not understand the physics of the process. Quattro, xDrive, 4Motion All these systems have their own nuances, but the basic principles of getting out of uncontrolled sliding remain the same.
First, it is important to understand what happens to the car when the grip is lost. The rear part begins to overtake the front, and the car turns across the road. The driver’s response in the first fraction of a second determines whether it will end in a slight scare or accident. It is critically important not to panic and not to make sudden movements with the steering wheel or pedals, since all-wheel drive is extremely sensitive to thrust drops.
Process physics and all-wheel drive types
Before proceeding to practical actions, it is necessary to understand how exactly the torque is distributed between the axes. There are three main types of systems, and the behavior of each of them in the skid is unique. Understand what system is installed on your Subaru Impreza, Audi A4 or BMW X5It will help you choose the right strategy.
The first type is a permanent all-wheel drive with an interaxial differential. Under normal conditions, the moment is divided, for example, 50 by 50 or 40 by 60. When skidding occurs, the differential tries to align the rotational speeds of the shafts, which can lead to loss of traction on all wheels at once if one of them is in the air or on ice. The second type is a plug-in all-wheel drive (Part-Time), which is normally rear-wheel drive. The third type is multi-plate clutch systems that shift the moment to the rear axle only when the front one is slipped.
- 🚗 Permanent all-wheel drive (Full-Time) provides better course stability, but requires careful operation of the gas.
- ⛓️ The plug-in front (On-Demand) often behaves like a front-wheel drive car until the moment of breakdown, after which I sharply characterize.
- ⚙️ Electronically simulated lock systems can “strangle” the engine when trying to level the machine, unless the stabilizers are turned off.
They can be useful for a beginner, but an experienced driver is often interfered with because electronics It reduces the thrust exactly at the moment when it is needed for alignment. Knowledge of the physics of the process is more important than blind belief in computers.
Algorithm of actions when skidding on all-wheel drive
When the skid has already begun, there is no time for reflection. Your actions must be brought to automatism. The first and most important rule is that you need to steer the wheel. skidward. If the car's feed is carried to the right, turn the steering wheel to the right. If left, then left. This counter steering helps to get the front wheels back on track.
The second aspect is working with the gas pedal. On all-wheel drive, you can not sharply throw the gas, as on the rear, or press it into the floor, as on the front. We need to find a balance. Smoothly add traction to the wheels caught, but not so much as to tear in the slip front axle. A sharp discharge of gas will cause a pecking nose and will intensify the reversal.
☑️ Checklist for skid exit
⚠️ Attention: It is strictly forbidden to sharply press the brake pedal during skidding. This will result in a complete loss of handling and a guaranteed 180 degree or more reversal of the car.
The steering wheel should be smooth, but fast. Don't make any sudden jerks. As soon as the car began to align, it is necessary to return the steering wheel to a neutral position just as quickly, but smoothly, so as not to go into a reverse, compensating skid. Oversteer (excessive rotation) on all-wheel drive is treated with gas and steering wheel, but requires high concentration.
Typical mistakes by drivers
Even experienced motorists often make mistakes in trying to fix the situation. The most common of these is “instinct inhibition.” Seeing an obstacle or feeling a loss of control, a person reflexively presses the brake. On a slippery road, it's fatal. The wheels are blocked and the car turns into an uncontrolled puck flying by inertia.
The second mistake is panicking with the steering wheel. The driver starts pulling the "drum" from side to side, trying to catch the car. On all-wheel drive, this leads to the fact that the front wheels constantly change the thrust vector, not having time to catch. As a result, the car continues to rotate around its axis. It is also common to make the mistake of “closing your eyes” or turning away from the direction of the impact.
- 🛑 Braking – Kills any opportunity to align the car.
- 🌀 Convulsive rotation with the steering wheel - does not allow the wheels to find a hook.
- 👀 Looking away from the trajectory – where you look, there and go (target fixation).
Another subtle mistake is trying to sharply turn off all-wheel drive or transfer the box to neutral. This deprives you of the only tool of control: the traction on wheels. The car will roll inertia, and you will completely lose the ability to adjust the trajectory with gas. Keep your cool and control. traction.
Why can't you throw gas?
A sharp discharge of gas on all-wheel drive causes the mass of the car to be redistributed forward. The rear axle is unloaded, the grip on the road drops almost to zero, and the skid is intensified many times. In addition, in some systems (for example, Haldex) when the gas is discharged, the clutch can open, turning all-wheel drive into the front, which changes the dynamics of the car at the most inopportune moment.
Working with Electronic Assistants (ESP, TCS)
Modern cars are equipped with many electronic safety systems. ESP (Electronic Stability Program) and TCS (Traction Control System) is designed to prevent skids. They slow down individual wheels and reduce engine power. However, in extreme conditions such as deep snow, ice or sand, these systems can interfere.
If you are stuck or trying to get out of the skid on a slippery section, the system can "strangle" the engine, preventing the wheels from turning and catching the ground. In such cases, experienced drivers prefer to turn off stabilization. This is usually done by a long press of the corresponding button or a combination of keys. However, on the public road completely disconnect electronics Not recommended.
| Situation | Recommended action | Role of ESP/TCS |
|---|---|---|
| Ice asphalt | Smooth gas operation, ESP enable | Helps by preventing breakdown |
| Deep snow/dirty | Strong traction, ESP is better off | Interferes by limiting traction |
| Sports track | Full driver control, ESP in sport mode | Allows controlled skiding |
| Rain/Meadow | Gas discharge, ESP active | Critical to Stabilization |
Even with the stabilization system on, physics is physics. If the speed of turning was too high, the electronics would not work miracles. It only corrects the trajectory, but it does not override Newton’s laws. Therefore The main safety factor is the speed chosen taking into account road conditions..
Features of the behavior of different AWD systems
As mentioned earlier, different manufacturers use different approaches. For example, the classic Torsen on Audi (until a few years ago) he was mechanically re-distributing the moment. It's very reliable and predictable. In the skid, such a machine requires gas: more gas - more moment goes back, less - in front.
Systems based on multi-disk clutches (Haldex and its analogues) work differently. They are reactive: first, the front wheels must slip into a slip so that the electronics understand that they need to throw the moment back. In the skid, this creates a slight delay. The driver feels the breakdown of the front, and only then the ass connects. This requires a little earlier counter-ruling.
⚠️ Attention: On systems with a Haldex clutch, you can not tow long in deep snow or dirt at the same speed. The clutch can overheat and disable all-wheel drive, leaving you with traction only on the front axle.
Japanese systems such as S-AWC on Mitsubishi or DCCD on SubaruThey offer different modes to the driver. The "Snow" or "Gravel" mode changes the logic of differentials, making the car more friendly on slippery surfaces. Using the right transmission modes is half the success.
Practice in safe areas. Understanding the behavior of your particular machine comes only with practice. Find an empty snow-covered parking lot and try to feel the moment of the skid start.
Prevention and preparation of the vehicle
The best way to get out of the skid is not to get in it. But if conditions dictate their rules, the car must be ready. This is especially true of tyres. Winter tires for all-wheel drive are mandatory. Summer tires on 4WD create a false sense of confidence that disappears when you brake on ice for the first time.
Also important is the condition of the suspension and collapse-descend. Uneven wear of tires or "walking" downfall can cause a sudden failure of one of the axles. Check tire pressure regularly: over-pumped tires reduce the contact spot, and under-pumped tires can lead to the destruction of the sidewall when they fall into the pit.
- ❄️ Use quality winter tires (spikes or Velcro) on all four wheels.
- 🔧 Watch for the serviceability of viscous scoops and transfer boxes.
- 🧹 Always clear the snow before driving, especially the headlights and sensors.
Don't forget the review. Dirty glass and headlights significantly increase the risk of an accident. The sensors of stabilization systems, sealed with snow, may not work properly. Preparing a car for the winter season is not just a replacement of rubber, it is a set of safety measures.
All-wheel drive helps to accelerate and get out of the snowdrift, but does not help to brake. The braking distance of an all-wheel drive car is the same as that of a mono-wheel drive, if not worse due to weight.
Psychology of Driving in Extreme Conditions
Skills of getting out of the skid are not only mechanical actions, but also psychological stability. Fear paralyzes, makes you make sudden movements. The trained driver acts calmly. He knows that a machine is just a tool and can be controlled.
It is important to develop the car’s feel through the steering wheel and heel. You have to feel when the wheels lose traction before the car starts turning around. It comes with experience. Don’t be afraid of the winter roads, but respect them. Respect for the elements and understanding the possibilities of their motor-car - the guarantee of safe driving.
Remember that no system can replace common sense. If the road is cold and you don’t have the experience or the right tires, the best solution is to stay at home or take public transport. Safety comes first.
Do I need to turn off the all-wheel drive when skidding?
No, it is strictly impossible to turn off all-wheel drive during movement or skidding. This will result in loss of traction and controllability. Transfer the transmission to 2WD mode only in the parking lot and on a hard surface, if the design of the car allows it.
Will all-wheel drive help on summer tires in winter?
All-wheel drive will help you to go downhill in the snow, but will not help to brake or enter a turn. Summer tires in the cold tan and lose traction properties regardless of the drive. It's extremely dangerous.
What do I do if the car is spinning?
If the car began to spin ("turner"), the main thing is not to brake. Work the steering wheel towards rotation to extinguish inertia, and try to align the wheels in the direction of travel to catch the hook. Brakes can only be stopped when the wheels are aligned.
What is the difference between 4WD and AWD in the context of skidding?
4WD (Part-Time) is a rigid axle connection, on asphalt in skid can behave nervously and require accurate gas operation. AWD (Full-Time) is a more flexible system, often with electronic controls, that forgives more errors and responds softer to driver actions.