Upgrading brake bulbs to Luxeon LED help...

[Quattro Pete]

I have a white single filament P21W bulb behind a red brake light lamp. This bulb is only used for braking (parking/position lights are separate). If I were to replace this bulb with Luxeon LED, which one should I get? The 1156-LX3 red?

Also, anyone using these particular ones? If it's not going to be as bright as a regular P21W bulb, then I won't bother.

 

[DracoFelis]

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I have a white single filament P21W bulb behind a red brake light lamp. This bulb is only used for braking (parking/position lights are separate). If I were to replace this bulb with Luxeon LED, which one should I get? The 1156-LX3 red?

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You will want a red LED behind your (red) lens, as that will give you roughly 3x the light of a white LED (of the same nominal light output) behind the red lens. The reason for this, is that turning "white light" into colored light, is done by "throwing away" any light not of the correct color (which "wastes" a lot of your total light). But when you put a colored light (for example, due to a colored LED) behind the same color lens, you get almost all the light going through the lens as "useful light"). So your choice of LED color (red) is the correct choice.

The big question in my mind is, would that "bulb" fit your existing P21W bulb socket? Assuming you (like most of us) have a 12v-15v electrical system powering the light, the only "unknown" is the bulb base (i.e. will it physically fit?). Since the 1156-LX3 is (apparently) designed to replace a (12v) 1156 bulb (or any other 12v car light that physically fits in a 1156 socket), the real question is: Is the base of your P21W physically identical to the base of a cheap 1156 bulb? If so, than that choice of LED will probably work for you (as a "drop in replacement"). But if the bulb base is not identical to a 1156 bulb base, you would likely have to swap your car socket (to a standard 1156 base) before using that LED module.

I did a quick google of P21W, and got a wide variety of descriptions. So it looks like P21W doesn't uniquely describe one bulb, but instead describes a family of bulbs?

Which makes it a little unclear about what fits your particular bulb base. You might try the Silvania web site, to try to identify the exact bulbs in your car:
http://www.sylvania.com/ConsumerProducts/AutomotiveLighting/LampReplacementGuide/

Or, (if the above bulb cross-reference) doesn't give you some useful info, you might just waste a buck or two to buy a stock 1156 bulb as a test. If the stock (cheap, incandescent) 1156 bulb works in your application, it's very likely that your choice of LED module will work as well (as that LED module appears to be designed to mimic a stock 1156 car bulb). OTOH if the cheap stock 1156 doesn't work (as a short-term test), than don't bother wasting your money on the LED module (as if the stock 1156 doesn't fit, then it's likely that the LED module won't fit either)!

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Also, anyone using these particular ones?

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I'm not using that exact module, but I do use a related one. On my CRX, I've currently got the "1157-LX3" (dual brightness) Luxeon modules for my combo brake/tail lights. My experience with them has been favorable overall. They seem to be very noticeably brighter (effective light going out the red car lens) than the stock 1157 bulbs I was replacing, and the light is a much more "pure" red as well. And the "turning on" (when I step on the brake) seems to happen almost instantly (unlike a normal incandescent bulb, which will take a fraction of a second to "warm up"). Overall, I really like my LED "upgrades" (except for the initial cost to purchase them, of course). However, with all the variables involved with LEDs, YMMV.

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If it's not going to be as bright as a regular P21W bulb, then I won't bother.

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I have no idea how bright a P21W bulb is. Is it about the same brightness as a stock 1156 bulb?

If so, than I would expect the Luxeon modules to be noticeably brighter (based upon my prior experience with other closely related Luxeon LED lights).

In fact, the Luxeon modules I'm using appear (to my naked eye) to produce about twice the effective light (through the car lens) than the stock 1157 bulbs did. So the extra brightness was very noticeable when I looked. However, since I don't have a "light meter", this is only a rough subjective observation on my part (so I'm not sure how close my subjective observations are, as I didn't have any test equipment to check).

NOTE:
If you have no idea how bright a P21W bulb is, than the (previously mentioned) suggestion of buying a cheap (one or two dollar) 1156 bulb as a "test" only (to see if the 1156 bulb will physically fit, and roughly how the light outputs compare) might be worth while, before deciding if you will get the LEDs.

 

[Quattro Pete]

Thanks so much!

I think I caused unnecessary confusion by calling it a P21W bulb. I looked at it again, and it actually has a model marking: 7506. If I'm not misaken, that's just another name for an 1156 bulb. Here's the 7506 (on the left) from my brake light next to an 1156A from my turn signal lens.

I took that 1156A (that's the only kind of 1156 I had on hand) and installed it in the brake light lense just to see if it'd light up. The left photo is the original 7506; the right one - 1156A.

It's not a scientific test (all exposure settings were kept the same though), but the intensity of both bulbs appears to be quite close. So, you're saying that Luxeon 1156 LX3 should actually appear brighter than these 7506/1156 bulbs? If so, I think I'm gonna give Luxeon a try.

 

[DracoFelis]

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If I'm not misaken, that's just another name for an 1156 bulb.

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The cross-reference I found shows the 7506 as fitting the 1156 socket. So at least in theory, you should be "good to go" with the RED 1156 Luxeon LED module you were looking at.

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So, you're saying that Luxeon 1156 LX3 should actually appear brighter than these 7506/1156 bulbs?

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The Luxeon 1157 modules I got, clearly seemed to be (noticeably) brighter than the stock 1157 bulbs they replaced. And since a 1156 bulb is very close to the "bright"/"high" on a 1157 bulb, I would expect the same to be true of the 1156 "bulbs". However, YMMV as I haven't personally tried a 1156 red Luxeon (as all my brake lights are also tail lights, and therefore use 1157 "bulbs").

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If so, I think I'm gonna give Luxeon a try.

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If your experience is anything like mine, I'm thinking you will like them. However, be sure to let us know how well they work for you.

NOTE: Be very sure to get the RED version of the Luxeon LEDs, if you are going to try using these as brake lights. As already mentioned, that is important, as matching LED color to car lens color will give you the best results (with the brightest possible light, and the purest possible color of the light).

BTW: I have first hand experience with this, as I once (when I was experimenting with which LEDs would work well in my car) put a white LED behind an amber (yellow) car "running light" lens. And while it did mostly work, the results were dimmer than I would have liked, and the color resulted in a slight blue/white "halo" on the "yellow light". But as soon as I swapped that white module for an amber one, those "issues" went away (i.e. more brightness, and no "halo" on the light color). So I have personal experience with the fact that you really do get much better results by matching LED color to car lens color (even if/when the original car light was just a white bulb)!

 

[Quattro Pete]

Just looking at these specs right now...

http://www.superbrightleds.com/specs/115x-xLX3.htm


It appears that the 1157 version produces more lumens than a comparable 1156 version.

 

[Quattro Pete]

Also just found this:

http://incursio.blogspot.com/

Search for "luxeon" on that page to find the part where he describes his experience with them. I guess it's all about the lens itself - YMMV as you say.

Those Eagle Eye Towers that he mentiones look interesting as well.

 

[RFIRE]

There currently is no LED replacement bulb offered at retail that works properly in a fixture disigned for a conventional filiment bulb; none. I have extensive experience with a number of comples LED replacement bulbs, red and white, and not one puts out the light output over the design area of a conventional bulb. However, there are several conventional bulbs that do put out more light over typical bulbs, including a new GE line.

Richard.

 

[DracoFelis]

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There currently is no LED replacement bulb offered at retail that works properly in a fixture disigned for a conventional filiment bulb; none.

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Really? You really sound sure, eh? Only problem is, you are speaking with certainty, when some people (myself, for example) have different experiences!

If what you said was true, than please explain how I was able to replace my brake lights with single red Luxeon modules, and the result was BETTER than the stock bulbs? i.e. My entire lens will filled with the light of the LED. The LED was NOTICEABLY BRIGHTER than than the stock 1157 bulb it replaced. The light was a much more "pure" red than the stock (white) 1157 (incandescent) bulb. The LED turned on/off slightly faster (avoided the aprox 1/8 second delay an incandescent bulb has). And finally (like all good LEDs should), they used less power (and should laster longer).

And my Luxeon amber turn signal lights, were also brighter than stock 1156 bulbs they replaced (and had the other advantages mentioned above). Now, I did have to swap out the flasher unit before replacing my turn signals with LEDs, to get the proper flash rate. But after changing the flasher unit, the amber LED turn signals were again "better than stock".

And FWIW I eventually even "bit the bullet" and replaced my "backup lights" (on my CRX) with extra bright white Luxeon 1156 modules (mostly so they would never "burn out"). And while "color matching the LEDs" (to the car lens color) gives you a large bonus in "effective light" (light through the lens) vs using a "white bulb", with backup lights you already have a white lens (so no extra "color matching" light bonus). And yet, even with the backup lights, I get around 90% of the light I previously got with the stock 1156 bulbs. I know this, because I ran an experiment to see how much of the driveway I could light up at night with my Luxeon backup lights vs stock bulbs.

And as already mentioned, the white LEDs were the only ones that produced less light than stock, and then only slightly less (the amber and red Luxeon modules were BETTER than stock bulbs). So while YOU may not have any personal experience with LED modules that work very well as "drop in replacements" for some stock car bulbs (when the car wasn't originally designed for LEDs), that doesn't mean they don't exist. At least for some bulbs (with at least some car lens designs), there are in fact LEDs that work very well as "drop in replacements". I know this, as I've converted almost all my external lights (except for the headlights themselves) on my CRX with good results. And I've also converted a lot of lights to LEDs on my wife's Civic as well (again with good results).

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I have extensive experience with a number of comples LED replacement bulbs, red and white, and not one puts out the light output over the design area of a conventional bulb.

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I'm sure you do have experience with a lot of LED bulb replacements that didn't work well. However, your lack of seeing a LED replacement that works well, doesn't mean that they don't exist.

And (as mentioned above), my experience has been quite different. When I set out to get LED bulb replacements, it was easy to find ones that behaved as you described (i.e. not filling the car lens and/or being too dim). However, at least with the car lens designs of my CRX and my wife's Civic, I was also able to find some higher end modules that didn't have those problems. Now, if you have a very wide car lens, even the modules I found/used (which I think have an aprox 130 degree beam angle) might not fully "fill the lens". But at least with mine and my wife's cars, I was able to find some Luxeon modules that did a very good job of filling up my car lenses.

 

[Master ACiD]

current none huh? i guess mine doesnt have tail lights then!

 

[RacerE7773]

I bought one set of 194 "LED" bulbs for my one bulb only plate light, and they didn't light up white like they were supposed to. I tried both bulbs, same results; they lit up blueish white. Not police light blue, but enough that it would have caused that to appear in my mirror.

As mentioned in my Nighthawk mini bulbs post I now have the Nighthawk 194 bulb in the socket and they are really bright.

 

[DracoFelis]

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I bought one set of 194 "LED" bulbs for my one bulb only plate light, and they didn't light up white like they were supposed to. I tried both bulbs, same results; they lit up blueish white.

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What you are experiencing is the slightly "bluish tint" to the "white light" of so-called "white LEDs". As you found out, almost all "white" LEDs have this slight bluish-tint to them (if you ever looked at the output of a "white" LED flashlight, you would likely see the same effect). This tint isn't huge (it's a bit like the bluish tint on older style florescent bulbs), but it is clearly present in most "white" LEDs.

In my case, that wasn't a problem, as I was already expecting it (due to previous experience with so-called "white LEDs"), and the light was still sufficiently "white" for my use. However, if that's a problem in your application (and apparently you did find it objectionable in your case), than you will probably want to stay away from "white" LEDs.

NOTE:
Both the red LEDs and the amber ones produce reasonably "pure color" (without this color-tinge "halo effect" you get with white and blue LEDs). As a result, putting a (high brightness) red LED behind a red car lens (for example, for tail/brake lights) can sometimes work very well (I know it did in my case). However, since most "white" LEDs are actually slightly modified blue LEDs, most " white" LEDs will have a very slight bluish tint to the "white light".

FWIW:
In my case, I went and and replace my license plate lights on both my CRX and my wife's Civic with "white" LEDs. However, I (personally) didn't find that slight bluish tint objectionable (for the plate lights) because: 1) The license plate is still easy enough to see at night (I got behind the car at night to check how much the plate was lighting up), and 2) I'm still putting "white light" on the plate (albeit "white" with a very slight bluish tint). So until/unless some cop objects (and I've driven right past cops with that plate light on without any problems), I'll keep the white LEDs for the plate (if only because they use less power than the incandescent bulbs, and the LEDs also shouldn't have problems with ever burning out).

 

[Master ACiD]

real white leds really do produce white light, its just that alot of vendors are cheap and use non white led's and market them as white (apparently real white ones are more expensive to produce).

also, underdriving the voltage of a white led will make it appear blue.

the led bulbs i bought on ebay came from hongkong. they had real white led's in them. a standard dual element turnsignal bulb had 21 leds on it. when i plugged it in the light was a dull white-blue. i found out the manf was underdriving the voltage, so i rewired it to give each led 3.6v when the cars electrical system was at 14v.
this made them about 3x brighter and also got rid of the blue tint.

with all that said, im not sure led bulbs are worth it. yeah thay have that cool factor, but a standard incandescant bulb works just as good from a practicality standpoint.

i actually disconnect the bulbs to my liscence plates. makes it hard to read the plate by a digital cop (camera radar trap) at night.

 

[RFIRE]

"Really? You really sound sure, eh? Only problem is, you are speaking with certainty, when some people (myself, for example) have different experiences!" DRACOFEILS

Yes, LED's light faster, and can use less power, and can last longer than conventional bulbs, but all of your statements about brightness were purely subjective. Objective testing by DOT has not found an aftermarket replacement LED bulb that meets DOT lighting standards when placed in a fixture designed for a conventional bulb. This is why DOT directs local police to ticket vehicles with clear stop replacement rear lighting units. There is no red bulb that meets the color requirements of DOT.

This does not mean that there cannot be a replacement LED unit that works as a replacement bulb, if and when it hits the street it will come with EU and or DOT certification markings.

Richard.