4 questions re: HID headlights

<div class='quotetop'>QUOTE(pola @ May 13 2007, 09:17 PM) [snapback]441472[/snapback]</div>

 

How long do HDI lights last? The left front bulb on my April, 2006 Prius lasted only 40,000 miles.

What do they cost to replace ? I replaced it at the dealer yesterday for a total cost of $522.05 ($323.49 for the bulb and $172.50 for labor - the bumper has to be removed to replace the unit, plus tax). Needless to say, I immediately turned off my day time running lights. I will turn them on manually from now on when conditions warrant.

Do they annoy other drivers ?? Not if they are properly adjusted.

 

I use my HID low beams as DRLs, since I strongly believe in the safety benefits of having them. I got my 2005 #9 ("BC"?) in April 2005, and both lights are still working fine, and they've been on for almost all of the 44k miles I've driven. (Granted, that's in fairly climate conditions in both San Diego and Albuquerque; I've read that temperature extremes can accelerate bulb failure.)

My understanding is that a headlight bulb replacement should should only require the engine "hood" removal, the black plastic over the forward portion of the engine compartment. It's the fog lights that involve bumper removal.

And I've seen people talking as low as 50 USD/bulb, although you might have to observe special precautions (don't touch them with bare skin due to oils causing premature envelope failure, etc). So I'm not too worried about it at this point.

 

My Right-Front light lasted 106K miles and I kept the lights on during the day. The bill, $335 per light (I decided to replace both) and $200 for installation was a real shock. Needless to say I will only use my light at night. I have never received complaints about the lights from other drivers.

 

If you are intertested in HID headlamps and headlamp glare, see:
http://dmses.dot.gov/docimages/p64/139655.pdf
then see:
http://www-nrd.nhtsa.dot.gov/Pubs/809-669.PDF

I wrote the first one.

P.S. When I figure out a simple way to have a low energy, long life, and effective DRL for my Prius, I will post how to do it.

 

How about a strip of LEDs running across the front of the car?

 

That would be the idea, but you really need ones that will give you the correct beam pattern (essentially identical to a turn signal lamp) and with an intensity of about 500 candela on axis. The only way to get that is to use replacement amber LED turn signal lamps that are used on heavy trucks. There are none that I have found that are compatible with the curvacious Prius nose without doing a serious nose job. I will keep looking. I only started looking yesterday (picked up the cute thing on Saturday!), but I have a significant background in motor vehicle lighting and I am not that hopeful yet that it can be done without surgury to get them mounted. For those who don't have fog lamps, the location of the empty holes is just too low to be useful for DRLs. There is a Hella DRL kit that uses filament bulbs is a housing that is oval in shape, only slightly wider than the fog lamp opening. Unfortunately, it is not LEDs, and it is too low. I will keep looking. Hella has an LED kit that is not yet available in the US. I will try to get info on it. It may fit, but again, its not a great location. I will keep in touch.

When I find something I will start a DRL thread so as not to highjack this thread. It looks like there is a lot of interest.

 

Bottom line about HID headlamps for the Prius: drive both types at night before putting a deposit on your next new car.

 

I bought my Prius at Koons Toyota in Annapolis. They do a new car owner appreciation night at a local hotel once a month...free dinner, some raffles and a lot of service hard sell.

I asked their service manager outright if HID bulbs were covered under the 3yr 36 mo warranty and he said "Yes."

Does that sound correct?

 

I hope you asked him for that in writing.

 

I have a new but related question:

When turning on the lights, there is the brighter "flash" before they settle into their steady state. What happens when driving during the day (lights off) and you need to flash at someone? Is there the same flash, or not? If not, how does that work?

TIA

 

Yes, there is the same flash, and it's not good for the bulbs. Flashing takes a toll on bulb life.

Tom

 

1.) What is the proper beam pattern for a turn signal lamp?

2.) Do you happen to know what the desired output is in lumens?

 

Answer to #1: The angles in degrees are relative to the lamp's emitting surface and its optical axis facing outward, measurement distance is 100 feet. (H=horizontal, V=vertical, L=left, R=right, U=up, D=down) The information is from Federal Motor Vehicle Safety Standard No. 108, Lamps, reflective devices and associated equipment.
minimum candela of:

500 @ HV axis, and 5L,0 and 5R,0
437.5 @ 0,5U and 0,5D
250 @ 10L,0 and 10R,0
187.5 @ 10L,5U and 10L,5D and 10R,5U, and 10R,5D
100 @ 5L,10U and 5L,10D and 5R,10U and 5R,10D
62.5 @ 20L,5U and 20L,5D and 20R,5U and 20R,5D

Answer to #2: There is no numerical conversion answer to that question. See: LightCalc Lighting Software Glossary

 

Interesting, my left front bulb is giving me problem now at 53k miles(2 yrs). It turns on initially. After driving around for few minutes, it goes out. I used the HID as daytime running light. I won't do it anymore or mod fog light as DRL.

 

The HID lamp works by having vaporized metallic salts conduct electricity. When the bulb capsule is cold (meaning the metallic salts are condensed on the bulb's interior wall) the bulb must have 10 to 20 kilovolts applied to it in order for it to conduct electricity. That electrical current excites xenon and other gases to emit light. That is the initial flash that you see. Very quickly, the deposited metallic salts heat up and vaporized and begin to conduct electricity. As that happens, the voltage applied to the bulb reduces to about 70 volts and remains at approximately that for the duration of the time that the bulb is energized. During this transition, the xenon gas stops conducting electricity.

For other HID lamps that we typically see in the world, street, stadium, and warehouse lighting, the starting process is much slower, lasting from a few seconds to a minute or more, to achieve the steady state intensity. This long transition period from off to normal intensity is unsafe for automotive lighting use. The automotive lamps must achieve their normal intensity within less than a second in order for us to see or be seen. Imagine that you flash your headlamps, only to have them emit some light 30 seconds later! Such performance is unsafe. So, federal law requires all headlamps to achieve their nominal intensity within a few seconds when initially turned on for nighttime use. There is no federal requirement for the flash-to-pass operation, however, the normal industry practice for flash-to-pass is much even quicker than that. That is why, if you do not have a halogen upper beam headlamp to flash, you can use HID headlamps in a flash-to-pass mode.

Why is it hard on the bulb? Because every time you initiate the process, that sudden jolt of high voltage causes deterioration of the internal constituents of the bulb. However, the bulb (if manufactured by a reputable lighting company, typically thoses used as OEM suppiers) is designed and manufactured to withstand this. Over its life, many thousands of hours, it will slowly decrease its light output (not that you will notice) because of this interior deterioration.

 

Its not legal to use a fog lamp in the US as a DRL. Fog lamps are not very effective either because of their beam pattern and low mounting height. I suggest that you use the amber direction indicators as a DRL; the mod is much simpler, and the amber lamps are much more effective. Unfortunately, the turn signal bulbs have a finite life and so you need to have spares in the glovebox all the time.

You can get a kit from Web Electronics. I have not installed it, but others here have and they seem to be satisfied. I want DRLs, too, and may end up going that way, but I am looking for a lower energy, longer lived solution by using an LED DRL. Hella makes some, but they are not yet available in the US. Also, they are white, not amber, and thus not as conspicuous.

 

I leave the headlight switch turned on continuously on my 05 (package 6). I have 38k + miles. So far, both lamps are fine, no noticeable dimming (though I might not have noticed since it would be very gradual).

I prefer using the headlights during the day since most cars with DRLs don't turn the tail lights on. On rainy or foggy days, tail lights make the rear end of a car, especially a gray or silver car much more visible.

 

Thanks! Very technical, but informative. Unfortunately, it doesn't help me feel any more comfortable about using the flash. This may just help me be less reactive to those #%^&OK*$# stupid drivers. (Oops! Gotta relax )

 

Since most of my driving is at night, and I'm approaching 40K, I guess I should have a spare on hand.

A quick search resulted in a couple of options, plus some basic installation instructions.

Can anyone tell me if there is a brand preference for bulbs?
Also, some detailed bumper/trim removal pics or tips would help.

Thanks...Dan.





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