"The average factory headlamp only provides enough range to warn the driver of an object on the road a few seconds before it’s actually encountered, so the importance of an effective lighting system is easy to understand," says ARB, supplier of IPF lighting.

"IPF engineers consider all aspects of performance when designing each lighting system, especially those related to real world conditions," says ARB. "By focusing light properly in front of the vehicle, IPF lights increase visible range thus improving your ability to react and reducing driver fatigue."

And anyone who has driven off-road at night in, say, forests or rough farm terrain will quickly discover that the standard lighting, no matter how good on-road, is useless. Most of the time, the driver is flying blind – when the lights are pointing up to the sky, because of the angle of the terrain, the driver will be wishing they were pointing down, so he can see where the heck to go next. When they’re pointing down, he’ll be wishing they were pointing ahead to illuminate what’s coming next.

The way around this is to use multiple lights aimed in various directions, including to each side of the vehicle.

Although extra lights are often seen on four-wheel-drives, the number of drivers who use them off the road is small. Hunters, emergency crews, people who live in remote areas and club enthusiasts who take part in night rallies or safaris are the most likely want to brighten their way, beyond what standard headlamps offer.

For the rest, auxiliary lighting earns its keep on-road, while making pre-dawn or late evening dashes to or from the skifields, or off-road trip.

However, auxiliary lighting also plays an important part on winch challenge vehicles and other extreme off-roaders competing in night events. Narva’s off-road lights were praised by Steve (Chip) Tjepkema, the winner of the Outback Challenge in Australia, who said: "They relieved all the eye strain during the night stages. It was just like daylight driving and gave us that extra advantage.

"For highway night driving and also through the special stages, the lights picked up the roos and made it safer for us. Decent lights keep you alert and make it easier on the eyes."

It’s always best buying the best lighting you can afford. When buying cheap lights, you may be getting only what you pay for. Apart from the important considerations of the quality of beam spread and other issues to do with the actual lighting, the cheap units may not be particularly well constructed and lack what it takes to endure the rigours of off-roading. Corrosion and condensation are two of an auxiliary light’s greatest enemies.

There’s also a caution with quality brands. Although of excellent construction, they may not have been designed with off-roading in mind and their seals may not be up to regular immersion in water and mud. Relatively few lights are designed from scratch as off-road lights. So it pays to ask around.

Another consideration is that, for use off-road, the lights must be well mounted, otherwise the beam may jiggle all over the place. It’s not just a matter of bolting them to a sturdy bracket on a steel bullbar, either. The lamp’s own mounting mechanism must be strong, durable, able to absorb constant vibrations and keep the reflectors where they were pointed.

Usually, lamps designed for rallying or sold for 4WD applications will have satisfactory mounts, whereas cheap dress-up lights wearing a brand name you’ve never head of, may not. The better-quality lamps usually use a swivel or ball-joint type of mounting.

Where a light is mounted can have an effect on its efficiency. For example, wide-angle lights are best mounted low, but you’d have to be nuts to put your expensive fogs under the bumper of your off-roader (although some do, manufacturers among them).

Among the lights made for heavy-duty use is the Narva Gamma Xenon HID. An aluminium housing, internally mounted ballast and xenon gas discharge globe makes the Gamma resistant to shock and vibration. The globe life is around 4000 hours, said to be eight times that of a conventional halogen globe and there’s a choice of broad and pencil beams.

HID lighting is energy efficient, producing three times the light with low power consumption, thus conserving the battery. A colour temperature of 4250°K (Kelvin) is close to daylight, making it more comfortable on the eyes. The HID technology is also used in the recently introduced top version of the Narva Ultima driving light range. It has the same lighting performance as the Gamma, but without the extra heavy-duty construction of the housing.

The Ultima is an excellent choice for 4WD vehicles and in addition to the Xenon HID model is also available with other halogen globes. Several 4WD vehicle manufacturers use the Ultima as original equipment, including Jeep.

Resistance to water is a key requirement of 4WD lighting for many off-roaders. The Hella HydroLux is the aftermarket's first fully submersible driving lamp. Designed and manufactured in Australia, HydroLux driving lamps provide what is said to be unprecedented levels of reliability.

Hella has developed a patented multi-chamber isobaric system for the HydroLux that prevents water ingress, whilst still enabling rapid service access without compromising long-term seal reliability

Hella says there has never been an auxiliary lamp especially designed for such extreme application conditions available before. The HydroLux 1000 FF stands up to the toughest climatic and geographic demands and is impressive on account of its excellent lighting performance.

It’s said to be the most significant advance in submersible driving lights for more than a decade, and the lamp utilises Hella's Free Form (FF) optics. FF optics are a computer-generated reflector design that increases the light performance, compared to a conventional reflector.

Each HydroLux submersible driving lamp carries a unique serial number, is individually tested to a depth of one metre and issued with a certificate of conformance.

One-way fitment ensures correct assembly and sealing and even the captive 2.5m cable includes double silicone insulation for maximum heat and UV protection while removing all plugs and joints from the areas most commonly exposed to corrosion and moisture.

Key features of the HydroLux driving lamp are:

Submersible up to 1m water depth without impairing functionality;

Water, dust and mud don't affect it;

A patented isobaric multi-chamber system prevents water penetrating the optical components, at the same time allowing quick access for on-the-spot maintenance without the seals being damaged. The correct position of the seals is guaranteed by the one-sided fit;

Excellent lighting performance thanks to the latest FF lighting technology with a modern clear-glass design;

Sturdy bracket system with precision adjustment;

Die-cast aluminium housing;

Captive twin O-rings and hexagon screws on the front of the retaining frame make quick bulb replacement possible;

Pre-installed 2.5m silicone cable; and

Upright mounting.

Foglights

Before you rush out and buy foglights, take a moment to analyse how often you actually encounter fog. They’re not much of a cost-effective investment for use just two or three times a year. You really need to live in, or often drive through, an area that has frequent fog before they’re seriously worth considering. But foglights have an off-road use as well. Travelling slowly along a dark trail, a set of wide-beam lights that not only covers the track ahead but really puts light to the sides, can make a big difference. Fog lights do this very well.

Driving lights

Relatively few four-wheel-drives have the high-speed ability to out-drive the beam of a good set of driving lights, so for our type of motoring, the combination of a spot or pencil-beam light with a driving light (or trying to get away with a set of spots in addition to driving lights) is probably un-necessary.

For example, a good mid-rangeHella driving light will send a beam more than 300m up the road while the high-line Rallye 4000 will project almost 500m and the mighty Predator, something like 700m. Most 4WD wagons will brake from 100km/h to a standstill in less than 45m, so the beam of even a relatively modest set of lights will provide plenty of time for reaction and braking.

Driving lights in the Narva range include the European-made Targa 200 and the more compact, rectangular Targa 240.

The 200 has a 200mm diameter lens and combines the performance of broad and pencil beam into a single lamp design. The 240 was first released as a broad beam lamp but has recently been joined by a pencil beam model with an H3 globe capable of punching light out to 500m.

The shallow depth of the housing makes it ideal for mounting on bullbars and it has a reinforced mounting bracket capable of withstanding punishment in the bush

For those who do want to combine a spot and driving light, the spot is best mounted on the right-hand side of the vehicle and the driving light on the kerb-side.

A great advantage of driving lights is that they provide a fairly wide beam, lighting up not only the road, but the verges and ditches, too and this effect can be improved according to how the lights are aimed.

If you think your normal high-beams do all this, you haven’t seen anything until you’ve tried driving lights.

There is a downside to all of this. Driving lights, in conjunction with the vehicle’s high beams, provide so much illumination that, when you have to return to low-beam because of oncoming traffic, everything suddenly seems to become very dark. The driver needs to be ready for this sudden change.

Shapes, sizes

Driving lights and foglights usually come in round or rectangular shapes. The shape generally makes little difference to the characteristics of the beam (although bear in mind top-rung lamps are both large and round and there must be a reason for this); the alternative styles are there mainly for styling and fitment reasons. For example, on small four-wheel-drives such as Suzuki Samurais and their kin, it may not be possible to fit big round lights, whereas smaller, rectangular units will go in nicely.

We’re also seeing the arrival of very small projector-beam lamps using compound elliptical reflectors. Their advantage is their small size – great for placement and not restricting airflow to the radiator; but the cheaper ones may not offer very good beam penetration or spread. The more-expensive brands work much like the conventional units. PIAA makes a variation on the theme. They’re not super small, but not too big either and they’re sold as fill-in lights rather than for long-distance driving.

Wiring

There’s no point buying a good auxiliary lamp and hooking it to the juice with inadequate wiring and more than there is having your V8 running on six cylinders. Because good wiring has such an effect on a light’s performance, many top brands include a full loom and a decent switch, all designed to let the volts get to the filament. Even then, some cautious light-fitters will throw the factory stuff away and go to even heavier wiring and switchgear. The relay, too, needs to be a quality unit and a good one may be included in some of the better auxiliary lighting kits.

Finding good gear

You can be assured that even modestly priced lighting from well-known companies will be of good quality. What’s not so certain is the quality of cheap "generic" lamps that might carry a brand name you’ve never heard of, or carry a house brand name. We’re not saying these are no good; rather, you need to check them more carefully.

Unfortunately, there’s no way for the average consumer to compare the beam pattern until they’re fitted and switched on at night, but you can examine other aspects. Check the thickness and quality of the body. Is it made of a metal, alloy or is it plastic?

Plastic doesn’t necessarily mean bad. Some high-quality lights are of rugged polycarbonate or polycarbonate and metal; but you don’t have to be a genius to tell them from the rubbish. Look at the finish and the quality of the mounting attachment. Can the mounting bolt fall off into the body cavity of the light?

Some lamps are very much built to a standard, rather than a price. Hella’s HydroLux driving lamps for example use premium die-cast bodies and brackets made from custom alloys to ensure maximum corrosion resistance and superb mechanical protection of the optical components. Oven-cured UV resistant polyester powder coating provides a low-sheen finish to ensure many years of service even under harsh sunlight conditions.

Other lighting

Four-wheel-drivers often need more than just good frontal lighting. When reversing on the trail in the dark, you may find out too late that your backup lights give a pretty pathetic amount of illumination. This is why a lot of serious rigs have one or more larger, more-powerful reversing lights. A common application is to use a floodlamp/work lamp mounted quite high and suitably aimed. This has the added advantage of being able to be used as a worklight if repairs have to be carried out at night, and is useful for helping to illuminate night recoveries. Although Hella isn’t the only source of such lights, the company’s range is particularly extensive and includes round and oblong designs, some of which have built-in handles to assist with aiming. Among them is the FF worklamp range, intended for agricultural or other machinery but very useful for the back of a 4WD.

Any 4WD that ventures into the dark should also have an auxiliary hand-held lamp that can be plugged into the cigarette lighter.

For example, the ARB network sells the 4x4 Adventure light, a tough, compact and lightweight 12-volt fluorescent suited to numerous outdoor activities. The light intensity is high, yet the light draws just one amp. It will work from a standard 12-volt power socket in your vehicle, or a portable battery pack and comes with a 5m power lead incorporating an in-line switch, dual hanging points, and a canvas storage bag.

Watch the voltage

Because of used Japanese imports, many four-wheel-drives in New Zealand have 24-volt electrical systems. You can gather what’s going to happen if you start plugging 12-volt lights into a 24-volt system! Most lighting manufacturers offer 24-volt options, so make sure this is what you’re getting.

Portable lights that plug into cigarette lighter outlets are less-widely available in 24-volt and many owners of 24-volt vehicles have fitted step-down transformers so that they can use 12-volt accessories of all kinds.