The days of the headlight washer system could be numbered. More and more car manufacturers are quietly removing it from the trim. But then it’s this system that ensures that premium headlights provide the best visibility and also prevent glare.
The headlight washer system (HWS) has been around for almost 50 years. For the first two decades it was pretty much only used in cars in and from Scandinavia – mainly Sweden – and it was even mandatory for some time. The reason was that the systems, which still involved small wipers back then, provided far better visibility in foul weather. The high-pressure system – also referred to as a “shower” in the motor trade – only followed later and is now almost exclusively built in.When xenon lights first found their way into cars at the start of the 1990s a new reason came to light. The HWS prevents the headlights from producing excessive glare when they’re slightly dirty. That’s why washer systems became mandatory for this new technology. And to be precise, not just for xenon headlights but all headlights in which the light sources would produce more than 2000 lumens in dipped beam. This is the case for standard 35 W xenon lamps with 3000 lumens.
As little as a fine salt film has the effect of a diffuser, interfering with the distribution of light. The light is then no longer only projected onto the important parts of the road but also into oncoming traffic and rear-view mirrors. This has unpleasant consequences, with headlights such as halogen ones, which are normally weaker, dazzling more with a thin dirt film than clean xenon headlights.
With increasing dirt, glare gets nullified by the thick dirt film or in snow. Unfortunately this also dramatically reduces the headlight range, falling from typically 60 or 70 meters to below 30. In the case of very persistent dirt, you’ll only get as much light on dipped beam as you’d get from parking lights with a clean headlight. Actually, drivers ought to stop every few dozen kilometers and clean the headlight covers manually. But who would ever do that? So HWS is really useful, even for halogen and other headlights in which lamps remain below 2000 lumens. In most cars that are currently available HWS has sadly disappeared from the trim. Apart from the desire on the part of car manufacturers to cut costs, this has a lot to do with the additional weight of the larger water supply and accommodating it in an increasingly cramped engine compartment.
It would be a bit of a joke though if designers were also behind the downfall of HWS. In any case, experts like to spread rumors that apparently visible nozzles in fenders “ruin the whole front design”. But then there are these neat telescopic nozzles that only come out when they’re actually needed and remain pretty much invisible the rest of the time. They just cost a bit more.
Washer systems are no longer available in a lot of cars, and that doesn’t just apply to budget vehicle classes. In some models they’re deeply hidden in the price list for extras, but they’re generally still available. In other cases, manufacturers have them installed in all other countries but their own. In Scandinavia, for example, such systems are still commonly used. It’s probably worth insisting on a washer system in other countries as well. Not always, but sometimes, the dealer can order the foreign equipment ex works if he is willing to go the extra mile.