Munich - Autumn and fog go hand in hand. Fog lights illuminate the edge of the road more effectively and help drivers to steer more safely through the thickest pea-soupers. Unlike rear fog lamps, they are not mandatory by law and thus are not part of every car’s standard features; however, they are generally easy to retrofit. TÜV SÜD’s experts have five tips for drivers.
Perfect fit: “The easiest fog lights to retrofit to the vehicle’s front bumper and electrical system are lights that the manufacturer already installs in other models of the car or as an optional extra”, explains TÜV SÜD’s Eberhard Lang. Well-known automotive brands also sell tailor-made fog lights and kits for some car models. In addition, there are hosts of more or less universal products. LED fog lights are a current favourite.
Well positioned: Your car bumper may already have an integrated recess designed for the installation of fog lights and covered over. Sometimes the bumper has a marked section which is easy to cut out; however, if the bumper is truly virgin territory, the provisions of the law must be observed. Fog lights must not be fitted lower than 25 centimetres above the road surface and may not be higher than the height of the dipped headlamp beam (passing beam), with a maximum mounting height of 80 centimetres. “But make sure that the distance between the fog light and the furthest point of the vehicle’s contour is no greater than 40 centimetres”, warns Lang.
Clever cabling: Connecting fog lights to the vehicle’s electrical system is not a problem if the car manufacturer has already made provisions for this eventuality. Sometimes cables are installed as far as the fog light installation points; in some cases, tailored connections may be available from workshops as spare parts. The same applies to the relay switches for the system and the fog light switch itself. Lang’s professional advice: “If there is no space to install a separate switch, many car models offer the option of installing a combined switch for fog lights and rear fog lamps.” Universal cable sets are available for cars that have no provisions for retrofitting.
Correctly connected: In today’s cars, data buses are used to control and monitor numerous operations. In this case the software must be updated to include the retrofitted fog lights – usually an easy task for a professional garage. However, problems may arise if fog lights of a different brand from the original are installed in a car with a headlight monitoring system that also includes fog light bulbs. “If the power uptake of the new fog lights is not identical to the level pre-set in the car’s electronic system, a fault message will result”, warns Eberhard Lang. This problem may occur with LED lights, for example. The expert advises checking this issue with a garage before purchasing the fog lights.
Correctly used: Germany’s traffic regulations stipulate that fog lamps may be used when fog, rain or snow “significantly impair visibility”. Driving with parking lights and fog lights is permitted if weather conditions require it, but is usually not worthwhile. In conditions of dense fog, TÜV SÜD advises using fog lights together with dipped headlights to avoid restricting visibility. Don’t forget to switch off the auxiliary lights when the fog has gone – particularly rear fog lamps, which would otherwise dazzle the traffic following. And remember that rear fog lights may only be used when visibility falls to below 50 metres and at top speeds of 50 kilometres per hour.