Hmmm... I'll have to poke around the 463 EPC a little bit.  Thanks for the heads up, Dutch.

And Daniel, as long as you're developing a bulb, lets go for that "Super Supreme Pizza" we've talked about before and add better durability into the mix. 

I run the Silver Star bulbs from Osram/Sylvania.  I've tried "brighter" that is higher wattage bulbs before but the always rattle apart in less than a year.  The silver stars are the best combination I've been able to find a as a happy medium between durability and seeing.

-Dave G.

In order to answer this question, I'd need to know what you think "'R' type HID bulbs" are. If you're asking why Osram, Philips, Sylvania and Hella make HID burners rebased to fit into halogen headlamps, the answer is "they don't". All kits thus advertised are advertised falsely, usually on the shaky basis of a Philips, Hella, or Osram ballast being included in the kits. If you're asking why those companies market bulbs with blue glass, that's easy: 'cause there's a market for bling!

N/A. The photo you show does not depict a Hella-made reflector. I made reference to a test of a Xenon "retrofitted" H4 7" round headlamp "very similar to the Hella reflector you used" in a previous post; the Hella reference was erroneous—see? I'm human, too! The photo you posted shows what is probably a Chinese-made lens-reflector, which could've been sold under any of many brands (Eaglite, Eagle-Eye and Maxtel are three names commonly applied to those particular optics, though there are others). It doesn't really matter, though—the laws of physics don't know or care whose name is on the headlamps you use!

I appreciate that, I guess, but certainly if you think there's some fact I've got wrong, you ought to bring it up; I would be pleased to discuss it in public -- as long as we don't confuse opinions, guesses and preferences with facts. As far as my business, I stand on my reputation as a straight shooter, and I sleep well at night, so I'm not sure what basis you might have for making an attack.

Already covered. The new lamps will use H13 bulbs, which are the latest 2-filament headlamp bulb design (released late in 2003, compare H4 which was released late in 1970!). Lifespan of H13 is considerably longer than that of H4. 

 Are you moving the thread or just making a copy to put in the new forum?  There seems to be information in this thread that is specific to the gwagen.

:cheers:
Chad

And likewise, I apologise for upsetting you with my tone.

Ah, OK, you are referring to bulbs like D1R, D2R, D3R and D4R as well as the abortive Type 9500 bulb. They are indeed intended for use in reflector-type HID headlamps, but what I think is missing from your understanding is that the reflectors used with these bulbs aren't the same, optically, as reflectors used with any of the many different types of filament bulbs. Conceptually they're the same (quasi-parabolic reflector with light source located at or near the focal point), but at the functional level of the actual surface contours that collect and direct the light, each reflector design is specific to the single type of bulb it takes. The same goes for any lens optics that may be present—they are not the same for any two types of filament bulbs, and they are not the same for any filament bulb vs. any HID bulb. I would like to encourage you again to read this, which goes into greater detail on the optical differences involved. One good "real world" way to see the differences is to take even just a fast look at the halogen and HID headlamps on W210 E-klasse vehicles. Same concept (single fixed light source at focal point of bowl-shaped reflector), same overall packaging, but radically, visibly different optics. They just are not interchangeable, optically.

Every "HID kit" advertises that it places the arc exactly where the filament was. That's not sufficient to address the problem, for the arc light source has a size, shape, orientation and distribution of intensity very different to any filament. The arc is crescent-shaped, has its highest intensity and steepest light/dark gradient at the ends, and its shallowest light/dark gradient at its edges. The filament is cylindrical, has its highest intensity and steepest light/dark gradient at the edges, and its shallowest light/dark gradient at its ends. Note the complete opposition of the two sources' distribution of light, edges vs. ends:

As a couple of asides for your interest, the reflector-type HID bulbs were not developed specifically to suit Mercedes' desire to carry on using reflector-type optics. The reflector- and projector-type bulbs were developed in parallel from the start, because all of the lampset makers and automakers who were in on the conceptual development wanted both optical options available. Also note that Hella don't manufacture bulbs. They buy them from all over the world, label and box them, and sell them.

Interesting. Perhaps when you get a moment, you can post a good, clear, close-up picture of the lens with the lamps turned off, or if not, you can post all the lens markings (letters, numbers, symbols, words, names...). It doesn't appear to be a Bosch, and it's not a Hella, and most of the rest of what comes out of Germany is rebranded stuff from China, but let's see what it is you have. It's also not a Valeo/Cibie/Marchal (France/Belgium), not a Carello (Italy), not an Autopal (India), but it could be a Zelmot (Poland) or a Wesem (Taiwan, rebranded through Germany). Outside chance it could be a ZKW (Austria), but those are almost never seen.

Correct, but they are all optically engineered from the start as reflector type HID systems. They are not tungsten-filament optics retrofitted with an HID light source, and that is the critical difference.

That would be the Sylvania Xenarc kit you're thinking of. I have much closer knowledge of that system than is decent, given its utterly abysmal performance and legal noncompliance, for I was hired nominally to try to clean up the enormous mess that resulted when Sylvania hired a one-man fly-by-night with a Taiwan connection to supply those Xenarc kits. The product was past deadline and wasn't even close to legal compliance. The fly-by-nighter had already spent what Sylvania fronted him, and wasn't willing to put any money into fixing the design, which was a product of a Taiwanese guy with a workbench in his basement (no foolin'!). He was able to design adequate glovebox lights, but certainly not headlamps, which are optical devices (could you devise a working pair of eyeglasses in your basement...? Neither could he!). Performance was stinkin', materials and construction quality were equally dreadful, and I resigned when I was asked to sign off on falsified DOT compliance tests out of Taiwan. The kits were remaindered out as surplus and quietly discontinued. I never did find out whether the lack of legal action against fly-by-nighter was because Sylvania simply made a giant blunder and wanted to get past it as quickly and quietly as possible, or because there was more going on between the two parties than I was aware of. There was a local tour bus company here that equipped all their buses with those lamps shortly after they came out. I got to see 'em most days on the highway, and sealed beams started going back in within four or five months as the Xenarcs would fail. There was nothing the matter with the bulbs or ballasts, which were standard production Osram items out of Germany. But the lenses would crack, craze, cloud up, turn yellow and/or fall off, the reflectors would fog up, and even in brand-new perfect condition, the light output and focus was much poorer than a standard off-the-shelf sealed beam. These lamps were bad for a different reason than HID "retrofits" into halogen optics: simple poor or absent engineering and quality!

Not long ago, ValeoSylvania (a North American joint venture that primarily supplies lighting equipment to the North American automakers) introduced a range of aftermarket BiXenon headlamps. Their XE7 is a projector-based 7" round unit that's rather good indeed but doesn't fit directly in place of a 7" reflector headlamp (bucket mods are required since the unit is larger in several directions than a conventional lens/reflector). They also offer a reflector-based BiXenon headlamp in the 7" size format, their item number XE7R. I'm not as keen on this one as on the XE7, because beam focus and formation aren't as good, but even so, focus and formation are very much better than with the aforementioned Xenarc lamps or a "retrofit" of HID bulb into halogen optics. You can see and buy ValeoSylvania's lamps here at their retail site. Other lampset makers have BiXenon 7" round units under development, and as with all competitive products of any given type, there will be a range of overall performance and an array of different decisions regarding the various design, construction and performance options.

Meanwhile, fly-by-night guy brought another range of Taiwanese HID headlamps in, this time projector-based ones. His company is now in receivership, draw your own conclusions.

That's good that you went to the trouble, but as previously explained, subjective judgements of headlamp beam performance and glare just don't have any veracity—even if you're going by whether you get high-beam flashes from other motorists. A great deal of research has been done over the years, and it all shows that subjective judgements of beam performance and glare are virtually always very far removed from objective measurements, and that motorists in North America do not exhibit any significant predictability or consistency as to whether they flash in response to any given level of glare.

The vehicle is far too close to the wall to see accurately the overall beam distribution, but it is clearly visible to me that your HID beam distribution creates too much glare. (That is clear to me because I spend my days engineering and evaluating automotive lighting devices and systems. It would be unreasonable to expect someone not specifically trained and experienced in this field to be able to make such a determination.) As far as glare goes, it's a relatively simple matter of whether there's more/less than "x" amount of light at such-and-such points in the beam pattern. But seeing performance is much trickier, because it is heavily dependent on the intensity ratios between certain points and certain other points. This is why headlamp optics are complicated and very specific to one particular headlamp bulb for any given headlamp: Not only must the amounts of light at a variety of test points be appropriate on an absolute basis, but they must also be appropriate on a relative basis. A given intensity at the low beam hot spot, for instance, provides adequate seeing performance if foreground light is below a certain intensity and width, but that same hot spot intensity is wholly inadequate for minimally acceptable seeing performance if foreground light is below a certain intensity and width. And that's just one of many such situations. It's really not as simple as it seems on the surface.

The Osram 70/65w bulbs are physically and electrically compatible with any of the H4 headlamps used in any G-klasse, including the '02-up clear-lens units. The brake lamps can be improved by replacing P21W with P3497, which is a higher-efficiency bulb and produces 566 lumen (P21W produces 415 lumen). Earlier G-klasse models with amber turn signal lenses using a colourless clear bulb can likewise use P3497. Later-model turn signals with colourless lenses and amber bulbs can take Osram's Diadem variant of the PY21W bulb, the Diadem version is not subject to the problem made by the standard bulbs' dip-type amber coating (it bakes off and fades, causing the indicators to emit brownish-white light rather than the correct amber). Front position lamps and North American-market front and rear sidemarker lamps can take P3886x or P2886x bulbs (depending on specific fitment needed, glass wedge or metal bayonet base). These bulbs produce 85 lumen, while the standard bulbs produce only 30 (metal base) or 50 (wedge base). All of these special upgrade bulbs can be had in North America from Candlepower, sales@candlepowerinc.com .

Good questions, MBDT. On the 123s, I always recommend staying with the North American headlamp housings (originally equipped with a 7" round sealed beam headlamp and 5.75" H3 fog lamp unit). The original optics are poor — the sealed beam headlamps are junk, and the fogs, while of OK design, are mounted too high to be of much use. However, the universal nature of the 7" and 5.75" round fitments means you have *tons* of choices for what to put in the four buckets. There are a bunch of different 7" round European-code headlamp units that can be installed in place of the sealed beams. Many of them are poor, some of them are mediocre, and some of them are good to excellent. The smaller 5.75" buckets can be made to accept any of several high/driving beam units (wide spread, long reach, something in the middle), or auxiliary low beam lamps of various types, or one of each of two lamp types (there's nothing saying both buckets have to contain the same kind of lamp).

With the one-piece European/rest-of-world lamps, you get no options beyond round/square. The performance of either type isn't particularly amazingly good, though with proper bulbs and wiring it would certainly be better than the sealed beams...assuming you got *new* lamps made by a European maker, not the Chinese and Indian-made copycat junk that's flushing through the market these days. Used lamps are also not worth messing with, by and large, because most people judge and describe seriously deteriorated lamps as being in "excellent" condition.

Whatever lamps you wind up choosing, shop carefully, because there are also those who don't know and/or care about the difference between UK/Australia/Japan lamps (for use in left-hand traffic) and rest-of-world lamps (for use in right-hand traffic).

Now, how to pick a 7" E-code headlamp unit?

Cibies are my standard recommendation, and they are very good indeed, though Dutch prefers Bosch units, which aren't bad. I do have remaining stock on two different varieties of scarce and really excellent Marchals: Their flat-face H4 units, which kick the snot out of any other H4 headlamp made in any fitment (standard or model-specific), and their flat-face Amplilux units, which contain two separate reflectors and two separate quartz bulbs for low and high beam, in each 7" round housing.

Cibies: $62/ea
Marchal H4s: $139/ea
Marchal Ampliluxes: $239/ea

The Ampliluxes are flat-lens dual-reflector units that take *two* quartz bulbs, an H1 for low beam and an H3 for high beam. These ultrapremium lamps are no longer manufactured, but as I say, I do have new old stock remaining. They fit a standard 7" round bucket, have very good water sealing, the separate low and high bulbs mean you can install whatever wattage combination you desire, and the separate high and low reflectors mean the high beam aim can be adjusted independently of the low beam aim. This is the _only_ 7" round lampset with that capability, which is very helpful in dialling in the headlighting beam distribution on vehicles used in nonstandard conditions (off road, severe weather, high speeds, high
headlamp mounting heights, etc.). However, because these lamps were originally very expensive, and are now rather rare, they are relatively costly.

As for the difference between Marchal H4s and Cibie H4s (and the commonly-available Hella units): Take a look at
this. The link takes you to isocandela diagrams for three different 7" round H4 headlamp units. Why not photographs? Because photographs of beam patterns can be very misleading even if the photographer has the best of intentions, because pixels and film work in a fundamentally different way than human eyes. So, we look at more objective comparisons of different headlamps' beam performance. The way to do that is with isocandela diagrams, which are generated by a machine called a photogoniometer that measures the intensity of light produced by the headlamp through a large range of vertical and horizontal angles. are just
like topographical (elevation) maps, except the squiggles and lines represent amounts of light, instead of elevation above sea level. The beam pattern is correctly aimed as it would be on a car on the road, and each differently-colored line represents the threshold of a particular intensity level. Each diagram is plotted on a chart calibrated in degrees. Straight ahead is represented by (0,0), that is, zero degrees up-down and zero degrees left-right.

To get a mental approximation of the units and amounts under discussion here:

Parking lamp: About 60 to 100 candela
Front turn signal: About 500 candela
Glaring high-beam daytime running lamps (e.g. Saturn): 8000 candela

The parameters to pay attention to are the maximum intensity and its location within the beam relative to the axial point (straight ahead, dead-center of the diagram chart) -- the less downward/rightward offset, the longer the seeing distance -- stray light outside the beam pattern (primarily above the horizon) and effective beam width (contained within
the dark-turquoise 500 candela contour)

The lamp plotted at the top of the page is no longer produced, which is sad, for it is the best-performing lamp in this comparison. It is the Marchal H4 I offer. Note its extremely wide beam pattern, intense and well-placed hot spot, and very well controlled upward stray light.

The second and third diagrams are Cibie and commonly-available Hella 7" round H4 lamps, respectively. The isoplot of the Hella unit is almost identical to what you get from the early-type (round-window) European W123 glass-front headlamps, and pretty similar to what comes from the late-type (square-reflector) units.

Things to notice about these two diagrams:

The Cibie produces a much wider beam pattern than the Hella. The 1000 candela line of the Cibie's beam pattern extends from 25 degrees Left to 25 degrees right, while the 1000 candela line of the Hella extends from 18 degrees Left to 20 degrees Right. At a distance of 50 feet from the car, this means the 1000 candela-and-brighter portion of the Hella's beam is
10.5 feet narrower than that of the Cibie. The 300 cd contour of the Cibie's pattern is *far* wider, extending from 43 degrees Left to 50 degrees Right, compared to 26 Left to 25 Right for the Hella. This means the overall useful width of the beam pattern at 25 feet from the car, as perceived by the driver, will be 40.7 feet for the Cibie and 22.3 feet for
the Hella.

The high beams for these two lamps (isocandela diagrams not yet scanned in) are very similar in overall performance and amount of light -- the critical difference is that the Cibie's high beam hot spot is located closer to (0,0) and closer to its low beam hot spot. The Hella's high beam and low beam hot spots are separated by a fairly large vertical amount, such that setting the lows where they belong results in most of the high beam light going up in the trees, but pulling the high beams down so they
send light straight ahead puts the low beams 10 feet in front of the car.

Sorry, I do not presently have an isoplot for the Marchal Amplilux. With stock-wattage bulbs, its performance is comparable to the Marchal H4, with perhaps a bit greater distance reach and the ability to aim the high beam independently of the low. This independent adjustability means that in a high-mount-height situation, with 100w bulbs in the low and high beam reflectors, you can set the lamps up to give optimal distance reach on low *and* high beam. With high-mounted lamps, you normally have to keep a tight lid on low beam wattage or aim the lamps way down, which geometrically limits seeing distance. All this talk of high headlamp heights, of course, is primarily aimed at the Gwagen situation, not that of your W123!

As for what to put in the 5.75" inner buckets: That depends on your driving conditions, and where/when you need more light.

If you want to talk dollars and delivery, please send me an e-mail, dastern "at" torque "dot" net.