Do Xenon lights degrade? Is it worth replacing them?

[rlg43p]

Two of the cars in the family have OEM Xenon lights:

2016 Ford Kuga
2015 BMW 420i

These days the lights, particularly on dipped beam, really don't seem as good as I would have expected.

Given that they are on their original bulbs, I was wondering if these degraded over time? Is it worth replacing them with new ones?

Does anyone have any experience of replacing them and could comment on the outcome?

Given that these bulbs are about £65 each I'm not keen on replacing them only to find it makes no difference.

[Ranger 6]

I have a 2008 X3 which have D1S Xenon bulbs - a couple of standard Ring replacements (£35 each) have made a marked difference, so I'd say yes.

[GeniusOfLove]

Yes they do degrade, can be well worth replacing them.

[sticks090460]

Yes. Yes.

[rlg43p]

Thanks for the replies. I will get some ordered.

[LunarOne]

While the bulbs themselves do degrade due to deposits on the inside of the glass, the majority of the degradation comes from the optical system which gets darker over time due to various effects. There are reflectors behind the bulbs which push the light forward through the optics also degrade due to heat. The only way to restore the full output is to replace the reflector too, which I believe often necessitates replacing the majority of the headlight unit. Last time I looked into this, there were some companies in the U.S. who supplied replacement xenon innards, but I can't find them after a quick google.

[Ultra Sound Guy]

My 2008 Jeep has HIDs and I was never happy with them.
I bought a new pair off Amazon and the difference was staggering!

[rlg43p]

LunarOne said:

While the bulbs themselves do degrade due to deposits on the inside of the glass, the majority of the degradation comes from the optical system which gets darker over time due to various effects. There are reflectors behind the bulbs which push the light forward through the optics also degrade due to heat. The only way to restore the full output is to replace the reflector too, which I believe often necessitates replacing the majority of the headlight unit. Last time I looked into this, there were some companies in the U.S. who supplied replacement xenon innards, but I can't find them after a quick google.

I suspect it is not practical to replace the reflectors or headlights themselves.

I am going to replace the bulbs and will update this thread with the results. I'll start with the Kuga and if the results are good then I will do the BMW afterwards. I'll take some photos and upload them if they show the difference.

[Robertb]

I changed the 11 yr old Xenon bulbs in my 996 with new ones.

They weren’t bad, but I changed them because Internet said they must be old and therefore degraded.

Made absolutely no difference.

[shtu]

Years ago, I replaced the bulbs in an A6, and also took out the projector lenses* and cleaned-off the thin layer of "stuff" that had built up over 5-6 years.

Massive, massive difference.


* This part was an industrial strength PITA, involving partially-dismatling the projector assemblies while inside the headlight, removing to clean, then reassembling inside the headlight.

[Acuity30]

Check that it's not road grime. I've been doing 30 mile commutes recently on country roads and I've been using the headlight washers as normal. Except one evening I parked up with lights on and had a look. Thick layer of white salty road grime all over them - so the washers weren't really doing much at all. Once I manually cleaned them the light output was significantly better, until they got dirty again.

[rlg43p]

So I upgraded the lights on the Kuga using:

Osram Night Breaker Laser Xenarc D3S (Dip)
Osram Night Breaker Laser H1 (Main)

Subjectively you can see the difference. The newer bulbs are much whiter and it feels light the light beam is more penetrating. This may become more evident when I take the car out and have to face oncoming traffic (which is where I felt that improvements were needed).

However the difference isn't as dramatic as I had hoped. Certainly if I had paid around £135 for these bulbs I would currently struggle to justify that cost.

I did take some photos, but I am not sure how much of the difference you can really see. It wasn't so dark when I took the photos of the original bulbs so it is difficult to conclude anything for definite because it was much darker once I had got the new bulbs installed.

Anyway here are photos for what it is worth.

On the left is the original bulbs and on the right the new bulbs. I may be convincing myself but I think you can see that the new bulbs on the right picture are whiter and have a more intense "reflection" off the grassy verge.

Dip Beam



Main Beam



In the pictures below the nearside bulbs have been changed, but the offside have not. I am not sure whether you will really see a difference in these photos on the forum, but the new bulbs did look whiter to the eye.

[mmm-five]

On my Z4MC, we remove the projector and wipe it of muck every 3 years or so as you get a build-up on the back of the lens which reduces light output.

Effect is something like this...

[rlg43p]

Perhaps this is what is needed, but I don't relish the task as it would involve removing the headlight and I don't know whether the projector would disassemble easily (or at all).

[Acuity30]

rlg43p said:

So I upgraded the lights on the Kuga using:

Osram Night Breaker Laser Xenarc D3S (Dip)
Osram Night Breaker Laser H1 (Main)

Subjectively you can see the difference. The newer bulbs are much whiter and it feels light the light beam is more penetrating. This may become more evident when I take the car out and have to face oncoming traffic (which is where I felt that improvements were needed).

However the difference isn't as dramatic as I had hoped. Certainly if I had paid around £135 for these bulbs I would currently struggle to justify that cost.

I did take some photos, but I am not sure how much of the difference you can really see. It wasn't so dark when I took the photos of the original bulbs so it is difficult to conclude anything for definite because it was much darker once I had got the new bulbs installed.

Anyway here are photos for what it is worth.

On the left is the original bulbs and on the right the new bulbs. I may be convincing myself but I think you can see that the new bulbs on the right picture are whiter and have a more intense "reflection" off the grassy verge.

Dip Beam



Main Beam



In the pictures below the nearside bulbs have been changed, but the offside have not. I am not sure whether you will really see a difference in these photos on the forum, but the new bulbs did look whiter to the eye.

My DD has a very similar beam pattern. Came with factory fit D1S HID dip beam and halogen high beam. One of the HIDs failed so I replaced the bulbs with some Amazon Novsight ones, just as bright if not brighter than factory, for about £30. Dissatisfied with the yellowy highbeams I then replaced those with LED 6500k Novsight LEDs. Plug and play, same beam pattern as halogen. The road now lights up like a UFO is beaming down from above, much safer and better visibility.

[LunarOne]

Acuity30 said:

My DD has a very similar beam pattern. Came with factory fit D1S HID dip beam and halogen high beam. One of the HIDs failed so I replaced the bulbs with some Amazon Novsight ones, just as bright if not brighter than factory, for about £30. Dissatisfied with the yellowy highbeams I then replaced those with LED 6500k Novsight LEDs. Plug and play, same beam pattern as halogen. The road now lights up like a UFO is beaming down from above, much safer and better visibility.

If the optics in his headlights are dirty, tarnished or corroded, then no amount of cheap amazon bulbs is going to do anything to restore the brightness that the headlamps had when the car was new. The only thing to do is disassemble the headlight units and clean everything. And since we already know that new bulbs have made a barely significant difference, then either the original bulbs were fine and the OPs expectations need to be reset, or the problem is still there and the headlamps need proper attention. I'm sorry but there's no getting around either physics or logic.

[Acuity30]

LunarOne said:

If the optics in his headlights are dirty, tarnished or corroded, then no amount of cheap amazon bulbs is going to do anything to restore the brightness that the headlamps had when the car was new. The only thing to do is disassemble the headlight units and clean everything. And since we already know that new bulbs have made a barely significant difference, then either the original bulbs were fine and the OPs expectations need to be reset, or the problem is still there and the headlamps need proper attention. I'm sorry but there's no getting around either physics or logic.

Maybe but that's just speculation since I've not seen the condition of his headlamps

[rlg43p]

Acuity30 said:

LunarOne said:

If the optics in his headlights are dirty, tarnished or corroded, then no amount of cheap amazon bulbs is going to do anything to restore the brightness that the headlamps had when the car was new. The only thing to do is disassemble the headlight units and clean everything. And since we already know that new bulbs have made a barely significant difference, then either the original bulbs were fine and the OPs expectations need to be reset, or the problem is still there and the headlamps need proper attention. I'm sorry but there's no getting around either physics or logic.

Maybe but that's just speculation since I've not seen the condition of his headlamps

And more than a little patronising as well as speculative.

Clearly he hasn't read the above report very thoroughly either.

Edited by rlg43p on Thursday 23 January 19:50

[LordHaveMurci]

Robertb said:

I changed the 11 yr old Xenon bulbs in my 996 with new ones.

They weren’t bad, but I changed them because Internet said they must be old and therefore degraded.

Made absolutely no difference.

TBF, 996 lights are st regardless.

And yes, I’ve owned one for many years.

[Acuity30]

rlg43p said:

And rather patronising as well as speculation.

This is PH, it should be water off a ducks back by now lol