One of the results of our big headlight survey (Stray light – Headlight survey) is that some drivers wait too long to switch from their daytime running lights to their low beams. I don’t want to bore anyone here by citing regulations and laws. What is more important to me is to clearly state that: daytime running light is not adequate for driving at twilight or full dark, even in the city, and the reason is safety.
We recently reported here about the autolichtblog traffic survey. One surprising result was that many cars were still travelling with only their parking lights on even in late twilight or in the dark.
Why is that? Is it ignorance, intentional?
It is neither. One possible explanation is the light switch on some newer cars with a light assistant. It does a fairly good job of regulating the lights automatically, and would have already turned on the low beams at the time of our headlight survey. But a lot of drivers apparently have not yet become accustomed to the assistant, and want to turn on their lights manually. The switch foils them, however, in this case. In several car makes, the “off” position is followed by an automatic setting. The positions for parking lights and full headlights come after that in the clockwise direction. By force of habit, drivers confused by this will turn the switch two clicks, which in the past would have brought them to the low beam setting. Today it is only the parking lights.
The automotive industry should rethink the logic of such switches.
This explanation naturally is erroneous when it comes to older cars, or those without light assistants. Another reason for using the wrong light could be the increased presence of daytime running lights on roads. Some drivers may confuse them with the parking lights, and view the latter as sufficient. Incidentally, the same effect was and is observed on Scandinavian roads, where foreign drivers will see natives driving with the daytime running lights. On the older Volvos and Saabs, they are in the same place as the parking lights. Consequently – or rather, incorrectly – foreigners follow suit and switch on their parking lights, which are much too weak. They have only five watts, while daytime running lights shine with 21 watts.
At the moment, xenon headlamps provide the best automotive light. But on a global average, only around 15 percent of all new vehicles are equipped with them. This is mainly due to the high surcharges involved, which put a pinch on the purchasers of smaller models, in particular. But xenon could get cheaper – thanks to a new technology.
The technology in question is known as 25-watt xenon and is a kind of “little sister” version of the currently available systems, which operate with a 35-watt high intensity discharge lamp. The technology used in both solutions is largely identical, so that the lamp developed by OSRAM for the new headlamps is the spitting image of the 35-watt version used hitherto. Indeed, hardly any visible differences can be discerned between the two headlamps. So what is it that sets the 25-watt xenon apart, and why is it cheaper?
Clearly, the difference lies in the electrical output, which is 10 watts lower per side with the new system. This results in a lower luminous flux of 2000 lumens. To compare: 35-watt xenon generates 3000 lumens. But this difference hardly affects the motorist’s visibility range. The 25-watt xenon illuminates the road almost exactly as far in a frontal direction. Only the width of the illuminated area is reduced – after all, the lower luminous flux must have some sort of effect.
Seen in this light, the new development may seem like a step backwards. What are headlamp and lamp manufacturers thinking of? What they’re thinking of is a threshold value in the approval regulations. An automatic headlight range control system and a headlamp washer system are compulsory from 2000 lumens upwards. And headlamp cleaning systems are a thorn in the side of many a car maker. Firstly, because they cost money and secondly, because they add unwanted weight to the vehicle, mainly in the form of the larger water supply required.
So the washer system can be dispensed with in cars fitted with the weaker xenon headlamps. Experts expect surcharges to drop to around 500 euros. The new system is hence mainly designed for small and medium-sized models. The 35-watt version will remain on the market. The lamps are not interchangeable.
The first cars to be equipped with the new xenon lamps are the new VW Beetle and the Audi A1. They don’t have a headlamp washer system, though it seems that they will have automatic range control, which the manufacturers are voluntarily including. And, dear car makers, I sincerely hope that you will continue to do so! For many drivers never use the manual solution that is operated via a control unit in the cockpit. Indeed, many aren’t even aware that their cars are equipped with such a thing. When loaded, these cars dazzle oncoming traffic, and this is something that should be avoided with the new, cheaper xenon light, too.