My car does something no other car I’ve ever owned does, and I wonder what the purpose is. It’s my first car with xenon headlights, and I have no idea whether the headlights being such has something to do with it.
When I turn on the headlights, they shift upwards a couple of degrees into driving position after a second or two. They’re not hidden, or pop-up, headlights. To look at the car when it’s off, you’d think the lights were already in fixed position for operation. What’s the purpose of having them rest in an ever so slight downward orientation?
It’s the levelling system that the xenon lights have to keep them pointed out of oncoming driver’s eyes on hilly terrain. It’s a servomotor system, and it’s off when the car is off, obviously. Down is the normal rest position, and when you start the car, the servos move the lights upwards.
No, they don’t compensate for the road level. For example, if the car is heavily loaded towards the rear, they will aim the lights down a bit. But they won’t do that because of a hill.
Well, let me correct myself. If you go up a hill, that may cause the back end of the car to squat a bit, and the leveling system will compensate. But it doesn’t really sense the hill, just how the car sits on it’s suspension.
Also at least on the cars I teach on, the movement of the headlights is dampened when the speed of the car goes over about 3 mph. Otherwise a bumpy road would have the headlights going up and down like mad.
and no, they don’t change angle for hills (up or down)
Yup, just like Q.E.D. said. Xenon lights while using very little power, produce lots and lots of light. If they were to shine into your eyes it would be blinding. Therefore the load compensators.
Has anyone else noticed some headlights seem to have a bluish beam that comes out maybe 10 or 20 degrees outside the direction of travel?
I see it in cars as they come towards me; when they are distant they are normal, but at some point about 10 or so carlengths away I can see a distinctly blue colour to the beam. Then when they get close it’s white again.
That shift must be what I notice in my wife’s car. (Audi TT.) I don’t drive it often, and last night was my first time at night. Turning on the headlights I noticed they seemed to flash very brightly for a second, then seemed to dim down.
I’m guessing that the ‘bright flash’ was the lights popping up, their settling into the downward position then gave the appearence of dimming.