Winter driving: what's the correct way to use my fog lights?

Tuesday, 19 June 2018

What's the right way to use my fog lights?

Seeing where you are going is a pretty vital part of driving, particularly in winter when visibility can be reduced even further by adverse weather conditions.

Of course your lights make up an important part of that whole 'being able to see' thing - again, particularly in winter - and, in fact, problems with lighting contribute to around seven deaths and more than 80 injuries each year on New Zealand roads, according to the New Zealand Transport Authority (NZTA).

While it may seem initially to be a simply case of 'It's dark, turn on your lights', automotive lighting isn't always that simple and there are laws around how many lights your vehicle can have fitted and how and when you can actually use them.

When visibility is reduced, extra lights are handy. But where and when should you use fog lights?

One of the most misunderstood lights on your car is the humble fog light. Despite the fact that the name says it all - they are for use in fog - they are a light that is a constant source of mystery and confusion for some people. So what exactly are they, and when are you supposed to use them?

* How to clear your windscreen

* What should be in your winter car survival kit

Fog lights, driving lights and daytime running lights are all very different.

* Silly questions about motoring in really wintry weather**

Fog lights (or fog lamps, if you prefer) are auxiliary lights fitted to a car to illuminate the road ahead in foggy conditions during the day and the night.

Fog lights should only be used in severely restricted visibility. So not here then, even at night.

They give off a short, wide beam of light that is designed to penetrate the fog, lighting up the area directly in front of the vehicle, while also illuminating the sides of the road.

According to the NZTA you can have up to two front fog lights fitted to your vehicle, meaning that if your car already has them fitted as standard, you can't add any more.

Driving lights aren't the same as fog lights. Don't confuse the two.

Front fog lights must be either white or amber in colour and should be wired so that they can be turned on and off independently of the main headlights.

Seeing and being seen are vital on foggy days. Make sure you know what lights to use.

They should only be used when visibility is 'severely reduced' - technically not just by fog, but also snow and heavy rain - and it is against the law to use them during clear conditions during either day or night, due to the risk of dazzling other drivers.

Aftermarket fog lights must be fitted symmetrically and as far as practicable towards each side of the vehicle. They cannot be positioned higher than the dipped beam headlights and must be able to be turned off from the driver's seating position. And if they are fitted, then they must work, with LED lights requiring at least 75 per cent of the LEDs working.

Broadly the same rules apply to rear fog lights, except for the fact that they must be red only.

But what exactly are the differences between fog lights, driving lights and daytime running lights? All of these lights may appear similar and be mounted in similar locations on the car, but all perform quite drastically different functions.

Driving lights are generally an aftermarket thing that provide auxiliary light to the high beam of the headlights and must be wired so that they turn off when the main headlights are dipped. Cars can have up to four main beam headlights, including driving lights, while motorbikes may have up to two.

Daytime running lights, however, are almost the complete opposite. They aren't there to provide any extra visibility for you - their sole function is to make your vehicle more visible to other road users during the day.

You can have up to two daytime running lights on your vehicle, which means that because most new cars come standard with some kind of DRL these days (often incorporated into the main head lights), you cannot fit additional ones.

DRLs can only be white or amber in colour as well. Some white bulbs may have a blue tinge which is acceptable as long as they aren't TOO blue (for headlights as well), and some LED DRLs (and headlights) have a purple fringe around the edge, which is also acceptable.