Winter driving tips

• Pull away and accelerate gently and progressively. In slippery conditions such as snow and ice, aggressive acceleration will almost certainly break traction at the driven wheels. The resulting wheelspin can lead to loss of steering control in a front wheel drive (FWD) car, or oversteer in a rear wheel drive (RWD). Both of these will prevent you from going in the direction you want and can be difficult to recover from. See our beginners guide to recovering from these situation below. Best practice is to keep engine revs low which will maximize your grip in winter conditions.
• Change up sooner rather than later, pull away in second gear if possible, and use the highest practical gear at all times. This reduces the torque at the driven wheels and will reduce your wheelspin – also a useful trick when trying to climb a slippery muddy hill.
• Avoid any sudden driver inputs (such as steering, braking, acceleration, gear changes etc). You only have a finite level of grip available and you don't want to overload your tyres unnecessarily.
• Brake soon, and gently. Be prepared to ease off the brakes (if you do not have ABS fitted) in order to steer. Locked wheels cannot steer!
• If you do have ABS, you'll be able to tell it has triggered by feeling a pulsing sensation through the brake pedal. If this has occurred do not 'pump' the brakes – rather keep a firm pressure on the pedal for maximum effectiveness. ABS is designed to help you steer as you're slowing down so use this to your advantage.
• Even if you do have ABS fitted, don't get into the habit of using the system unnecessarily - you'll be able to slow down in a shorter distance if you use threshold braking techniques.

Click here for a step by step guide to threshold braking

Guide to recovering from understeer and oversteer in very slippery conditions

Note: If you're an experienced driver you may be able to use other techniques to help recover from these situations, and these are covered in the dedicated oversteer and understeer articles.

Understeer is when you turn the steering wheel but find that the car has a tendency to continue straight on (Figure 1). Oversteer is when the car tries to spin round due to a lack of traction at the rear (Figure 2). Both situations are more likely on winter roads but can be helped using the same techniques (which should make things easier to remember).

Figure 1: Understeer - the car continues straight on despite applying steering lock

Figure 2: Oversteer - the rear of the car breaks loose and a spin is likely if not corrected

If you do find yourself in an understeer or oversteer situation do not stamp on the brakes in panic as this will make things much worse. First you need to try and get the driven wheels turning at road speed and regain some traction. Pressing the clutch or flicking an automatic into neutral will remove the influence of the engine and help get the wheels rotating at a more natural rate. Hopefully this will create vital grip for avoiding obstacles and allow you to progressively apply the brakes. Point the steering in the direction of intended travel, but don't use excessive steering lock, if a car starts to understeer many people will panic and apply as much steering lock as they can, but this can make the car less likely to make the turn. When traction is regained, be prepared to take off the steering lock quickly in order to prevent another slide.

Cars with electronic stability controls fitted

If you're car is fitted with electronic stability control systems such as DSC, ESP or other related acronyms the car can takes some of the control back from the driver by reducing throttle and braking individual wheels where necessary. In this case ensure the system is turned on (usually on by default) and make sure your steering is pointing in the intended direction - the car will do the rest. Modern traction and stability control systems will automatically make the best possible use of available grip and help you avoid an accident. If in doubt, gently use the brakes to slow to a halt.

Tyres

Depending on the severity of the conditions, it may be worth considering specialist winter tyres. These vary from a Mud and Snow (M&S) rating through to studded tyres for icy roads. Surprisingly, with the correct tyres fitted, driving in quite severe conditions can become remarkably easy – you just have to pay a visit to Finland or other northern countries in the Winter for a demonstration.

Manufacturers of winter tyres use several methods to increase friction and help maximize control. Firstly, the rubber compounds are usually softer which allows optimum friction to be reached at lower temperatures (this however does make them wear faster when used in warmer conditions on dry tarmac). Secondly, winter tyres can have small 'sipes' which are formed into the rubber within a tread block - these provide grippy edges which are especially useful when driving in snow.

Sipes: the horizontal lines shown in the image below. These provide grippy edges which help when driving in snow.

Winter tyres usually also have an aggressive block-like tread pattern which can help to dig into the snow and provide traction (also useful in muddy conditions). Finally, small studs can be fitted to the tyre and these provide a great deal of benefit when driving in icy conditions, although in some countries these are only permitted in the coldest months as they damage road surfaces. Studded tyres can also increase your braking distance when on a clear dry road.

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Snow chains

If you're driving in deeper snow, it might be worth considering using snow chains, or at least having some in stored in your car. These are fitted to the driven wheels and can provide dramatic increases in traction. If you do choose to fit snow chains, ensure the manufacturer's instructions are followed carefully or damage to your car could result.

Stopping distances in varying winter conditions

Graph 1 shows the dramatic difference in braking distance when on black ice compared to normal tarmac conditions, it's well worth bearing this in mind in the winter an adjust your driving style accordingly.

Graph 1: Stopping distance vs speed for dry asphalt and black ice

Source: http://www.csgnetwork.com/stopdistcalc.html

Friction levels in different winter conditions

The table below summarises the levels of friction available in different winter conditions - the worst conditions observed provided only approximately a quarter of the grip of dry asphalt.

Table 1: Grip levels in different conditions (calculated as the coefficient of friction)

For even more winter driving tips, please see our blog article here