some Qs about HID lights - BobG
I am currently running a Renault fitted with HID type Xenon lights for dipped beam which I find great and cause no apparent annoyance to other road users. Some general questions about this sort of lighting of which I know little.
What is the actual life of these lamps- the makers say "the life of the car " ?
Does the efficiency of this sort of lamp decrease with age as conventional halogen bulbs do?
On a purely legal point do I need to carry a spare lamp in Europe at a cost of £80+ even though I can't fit it ?
some Qs about HID lights - jc2
There is no legal European requirement to carry spare bulbs;the law merely states that it is illegal to drive with a bulb out.Some magazines/motoring organizations choose to interpret it as a requirement to carry spares.
some Qs about HID lights - BobG
Tahnks for that- should save some cash !
some Qs about HID lights - kithmo
In the eyes of the manufacturers, the life of the vehicle is usually to the end of the warranty, but IIRC about 10 years is the general concensus of opinion as being the normal lifespan for HID bulbs if they are of good quality. Not sure about degradation of the light though, IMO I would think not as it's a sealed bulb and the gas that is burning (if that's the correct term), not a filament.
some Qs about HID lights - Aprilia
Light output does fall with age. I changed some HID bulbs a couple of weeks back for a lady who claimed her lights 'had got weak'. I was suprised just how feeble they were. Whether this was just a rogue pair of bulbs or whether this is common, I don't know. They are still fairly new to the market. But its somthing to keep an eye on.
some Qs about HID lights - 547HEW
I have only used this type of lighting on my bicycle. (Light is made by Catyeye and is Stadium III type). It was rated at an equivalent tungsten bulb of 80W. No longer in production.

The light output has diminished with age. This would appear to be due to the glass lens being eroded/abraded by the hot elements of molten metal being produced by the arcing process.

some Qs about HID lights - BobG
Thanks for the information. I'll keep an eye on the output - bet they won't change them under warranty just because they're dimmer though.
some Qs about HID lights - Grease_monkey
My MK5 Golf was not fitted with HID light at build so could it get it converted with the HID lights that are fitted to HID golfs?
some Qs about HID lights - Rover25
My MK5 Golf was not fitted with HID light at build
so could it get it converted with the HID lights that
are fitted to HID golfs?

Should be possible, although cost might be prohibitive if you use genuine VW parts.
There are aftermarket kits availble for most cars, but they vary widely in price and presumably quality.