8KaboveMSL

Hi folks,

owner of a 06 C4S Cab (997.1) and I’ve been doing some research on improving the output of my headlights. I’ve read comments in several threads about how great the bi-xenon lights are (which I take at face value). I also read comments that suggested that the bi-xenon’s were standard w/ the S trim. So of course I had to go figure what those looked like and to understand whether I had those in my 997.1. Well it turns out that what I have are the standard headlights: one xenon projector w/ a halogen reflector below it.

Can someone clear up for me whether or not the bi-xenon headlights were standard on 997.1 S models or if they were an upgrade option?

I am going to do something to improve the headlights on my car. I looked at the Morimotos and they look awesome. They are a bit pricey so I am looking at just getting new bulbs to see if that does the trick. The bi-xenon thing is bugging me though. It if was a standard option in the S models, I’d be inclined to go in that direction instead of an aftermarket replacement.

alaris

My C4S has halogen high beams

Hootsama

I've always been curious about possible headlight improvement for my 2006 Carrera S even though I don't tend to do a lot of night driving. I double-checked my window sticker, and seems the Standard Equipment list includes "Bi-xenon Lighting Package." I am also interested in any feedback about whether there is improvement to be had here or if it's not worth the expense...

Breizh

Are you certain it is a bi-xenon, and not just a halogen bulb in a projector (for the top)? If I understand it correctly (big IF!), all Xenon are bi-xenon, meaning that the switch between High and Low beam is not really a "switch" but rather flipping a shield in the projector. Since the xenon bulb takes a while to get to temperature, more often than not you while also have a halogen high beam for "flash to pass" functionality.

Deven

My understanding is that Xenon bulbs are too bright as high beams. Thus some cars have 'Xenon' lights for the low beam and a separate light (Halogen) for the high beam.
Bi-Xenon basically means that 2 Xenon lights are used, 1 for high beam and 1 for low beam, however both filaments are in the same bulb. In order for the for the beam to go from low to high the light itself has to tilt (via the reflectors).

Now I am going to have to study my light as well, lol, but I was always under the impression that they were bi-xenon (also known as High Intensity Discharge (HID)) as I have not noticed a difference in light color going from hi to low beam. Maybe not as bright as LED's, but I think the Xenon are pretty good.

Here is decent video trying to compare them:

Breizh

Well I'll be damned... You're correct, there is a difference between Xenon and Bi-Xenon! I'm in the middle of completely refurbishing my headlight (new outer lens, new projector with better lens, new panamera-style shroud with DRLs, etc...) so that's definitely something to investigate. I bough a set of the new Morimoto LED assemblies, and, while I love the output, they do not play nice with the PDLS or the leveling system. I'll be selling those as soon as I complete the retrofit. I have a set of D2S-compatible LED bulbs on the way too, but I'm not holding my breath on their output.

BillB128

What Hootsama said.... The window sticker for my 2011 C2s lists the Bi-Xenon as standard. The Dynamic Cornering Lights were an option.

Petza914

Both my 05 C2S cars have the Bi-Xenon headlights. Didn't realize they weren't standard on the S models but I'd have to look at my build sheets to see if they were called out separately. Upgrading the bulbs to a good 6000k one helps, On my car, I bought a set of lights that someone upgraded the projector lenses in to clear ones instead of the diffuser ones and it's a noticeable improvement as well. I tried 2 different LED replacements for Xenons in my daughter's Audi Q5 and although the low beams are brighter and better, the high beams were useless. In one set you could barely tell they were on and in the others they pointed up into the trees, so the Xenon reflectors don't seem to work very well with the pinpoint light source the LED emits.

8KaboveMSL

Hi Pete, thanks for weighing in here. I went out yesterday to look at my headlights and they look identical to yours.



They also look identical to the headlights on the 997.2 GT3 in this video which the dude from Lightwerks refers to as the basic headlights.


I am now fairly convinced that I do have Bi-xenon (assuming you’re correct about yours). I’m not the original owner and don’t have the build sheet but the VIN Analytics readout doesn’t mention bi-xenon. I think @Deven ‘s explanation above for why there is also a halogen bulb sounds correct.

I know you like how your bi-xenon’s perform from other posts I’ve read while researching the topic. In my case tho, I feel like the bi-xenons in my C4S are not bright enough at night. I keep having to flick on my high beams when on roads that are not well lit at night.

I am going to try upgrading the bulb on them first. Although the Morimotos look really nice, I’m not ready to drop that much on new headlights. Plus I feel like if I’m going to upgrade the headlights to LEDs, I probably should upgrade all around (tail lights, side markets and parking/fog lights/etc).

Are you aware of the performance of these lights diminishing over time? Have yours changed at all since you first bought your car?

Petza914

I bought some Litronic bulbs (which means Xenon) and installed them in both my car and then my wife's so my lights are definitely Xenons and the bulbs are essentially a gas filled tube. A halogen bulb looks very different from a Xenon bulb, and the bulb type that's in your headlight might actually be embossed on the exterior lens of the light if you look very carefully. It is on other cars but I've never looked at the 997 that closely. My headlights don't seem to have deteriorated at all, but they've also probably only been driven 15k miles since I did that install 5 or 6 years ago or whenever it was and maybe a couple thousand of those miles were at night where they were actually being used. With 7 cars and the 997 not being a daily, it doesn't see a lot of use, but it's still my favorite.

preelude

Corrected:

Bi-Xenon headlights look identical to halogen. The difference is the projector inside, the bi-xenon projector is larger and has better optics and is of course HID. The Bi-Xenon unit has a shield that flips down when the high beams are activated that allows the light scatter further/higher.

The bi-xenon headlights still have a halogen flash-to-pass

8KaboveMSL

Super helpful! Thanks. Do you know if both the bi-xenon and xenon headlights also have the halogen bulb below the bi-xenon/xenon projector?

Petza914

Learned something today. I thought if they were Xenon they were the Bi-Xenon versions and people were just using those terms interchangeably. So there's Halogen, Xenon, Bi-Xenon, then the 997.2 versions with the Dynamic Cornering lamps. Are those all the headlight options on the 997s of both series?

Deven

I learned something as well. In retrospect it makes sense that there is a halogen bulb to flash, because Xenon lights don't instantly turn on (they take a 1-2 minutes to fully warm up to maximum brightness, but probably in a few seconds are bright enough), and when flashing it would not respond quick enough.

preelude

They do, the halogen bulb is for flash to pass. You can tell if a car has bi-xenon by the cut-off line of the beam changing shape when high beams are on, there is also an audible shutter sound from the exterior when the shield flips down.

Not 997, but it gives you an idea of the low/high beam: