Xenon Headlight Query

[JDM]

This may sound like a daft question but I noticed whilst driving down dark country roads the other night that the High Beam on the Z4 is so much brighter and crisp than just flashing the headlights. After investigation (sitting infront of a shop window )I've noted that when you flash the lights the H7 bulb above the sidelights illuminates but when you put the headlights on main beam the same bulb illuminates but the ellipsoidal lense part of the headlight where the xenon bulb is located also adjusts itself and becomes much brighter. Does this mean I have bi-xenon headlights or is this something completely different?

 

[Mattt]

It does this as xenons hate being cycled quickly.

 

[jan_tekin]

On the facelift the xenons do the flash as well.

 

[daveg]

Would seem so if source below is to be believed:

The four lamp Bi - Xenon systems on some cars (BMW for example) use beam deflection on one pair of HID Xenon lamps for main and high beams. The second pair of lamps contain standard halogen bulbs for the headlamp flash function, they are not used in normal running. HID lamps take a few seconds to reach full output and their service life is seriously reduced by flashing on and off, for these reasons they are not currently used for any flash function.

http://wikicars.org/en/Bi-xenon_Headlights

 

[JDM]

Thanks for the replies guys.. I always assumed Bi-Xenon lights would activate the xenon bulb when flashing like on the latest 3 series. Maybe this is on later cars as technology advances have made it possible for the bulbs to be flashed without affecting their service life? :?

 

[daveg]

Sounds right on to me.