HID Lights or Xenon lights

Lambofdave

Whats the difference?
Have xenon lights in my car now as I had problems driving at night before on the standard lights potentially looking at changing car and the standard lights are HID will i notice a big difference ?

MuppetCheck

They are basically the same thing. You will notice a difference for the worse going from Xenons to standard halogens. Personally I wouldn't buy a car without xenons again as I do a lot of driving in the dark and it makes it a lot easier.

You can retrofit HIDs into standard halogen lamps. I would only do this with projector lenses and even then you will be missing the self leveling and washers which are an NCT requirement I believe but you might get away with it.

It's worth trying the new cars lights out at night as there can be a vast difference between halogen lamps too.

Chimaera

There's a bunch of confusion out there about this topic. Xenon can refer to filament bulbs or gas-discharge bulbs.

In the case of filament bulbs, it basically means the bulb is filled with xenon gas instead of a halogen gas, usually to improve bulb life or output or both.

Gas-discharge bulbs are a completely different lighting technology: instead of passing a current through a wire filament, a capsule filled with gas (often xenon) is ionised to the point where it emits light. HID refers to high-intensity discharge, which is just a variation of this technology which emits a high specific light output.

Because of the different light output characteristics (position of the light beam and how it scatters) of each type of technology, each should really only be used in a lamp designed for that technology. That said, there are situations where you can get away with a HID capsule in a fitting designed for filament bulbs. Mostly that's projector headlamps, though occasionally it can work in reflectors: it's an expensive experiment though as a decent set of HIDs for retrofitting can be up to €200.

Some companies advertise special HID capsules which are modified to have similar light output characteristics to filament bulbs, but I've never seen an independent assessment of these and again it's an expensive experiment.

As MuppetCheck pointed out also, a simple bulb retrofit will not have the auto-levelling system and headlamp washers legally required for the use of HID bulbs (these are needed due to the higher potential for glare resulting from the technology).

If you want higher light output from your existing lamps, here are a few suggestions:

Make sure your headlamp lenses are in good shape: if they're scuffed and scratched, the light from the bulbs will be scattered around and lost. You can polish them back to health if they're not too bad, otherwise you might have to change them. There are a few threads on headlamp polishing in the detailing forum if you have a dig around.

Make sure they're correctly aligned and that the levelling motors (if fitted) are working correctly. If they're out of adjustment, more of your light output will be scattered around than directed onto the road. If the adjustment mechanism is damaged, replace the lamps.

If your headlamps are in tip-top condition and you're still unhappy, consider high-output filament bulbs to replace your standard ones. Osram do Silverstar and NIghtbreaker Plus lines, both of which I've used and been happy with compared to standard halogen bulbs. Bear in mind though that bulb life with these is typically shorter than a standard halogen bulb and they're more expensive.