4 questions re: HID headlights

How long do HDI lights last?
What do they cost to replace ?
Do they annoy other drivers ??

Consumerreports.org said the problem is the fake HID lights, with a blueish light, not the real ones.
They said the real HID's give better visibility to the driver, including out of the side of the vehicle (more than is necessary) which can blind oncoming cars. That does not sound safe.

Is this true ?

thanks,

1. I dont know. This is my first HID lights. but I heard they last a long time. Longer than normal bulbs.

2. Dont know the exact number but I heard they are expensive. $100+?

3. Yes they do and I like it that way. It only annoys the drivers when I'm cresting a hill and the lights are pointed up otherwise they are pointed to the ground and don't bother people at all. I've always hated when people don't have their headlights adjusted or driving with their brights on, or the annoying turck/suv driver just has their regular lights on and they still blind you. When ever someone flashes me I flash right back and honk the horn and if I have time I turn on the fogs just for added effect.

4. I think the HIDs look better than regular lights. I'm able to see more at night with them but they do take some getting used to.

<div class='quotetop'>QUOTE(pola @ May 14 2007, 01:17 AM) [snapback]441472[/snapback]</div>

I don't know the exact number of hours they nominally last, but they have a long life. Like any other discharge lamp, life expectancy is greatly influenced by usage. If you turn them on, then off, and on again, you take a hit on lamp life. If possible, you should always allow discharge lamps to cool between strikes.

Cost? Let's see, the cost for an entire HID unit is several hundred dollars. I'm not sure what the cost is for just the lamp.

Do they annoy other drivers? High quality HIDs, such as those on the Prius, do not annoy other drivers. The good units have very sharp cutouts that control the spread of the light. Cheap after market units lack the mechanical cutouts. Also, the Prius has auto height adjusters, which compensate for loads in the back and keep the HIDs from shining up into oncoming traffic.

Tom

Hi pola

HID (High Intensity Discharge) headlights basically work like an arc light. An instant high voltage surge alights the gas in the bulb. Interesting that the power consumption of the HID lights is actually less (35 Watts after they light up) than the Halogen 'standard' lights which are around 65 Watts. Lower power consumption and brighter light output... a win/win situation.

If you do a "Search" here or Google HID lights you will find many former posts and much information. As I recall, the bulb alone replacement runs like $250/bulb. In addition there's a 'booster' which provides the surge of power to 'start' the lights. Again, in my imperfect memory, the life is about 3,000 hours, a lot longer than the Halogen bulbs. If the 'booster' goes out, then there would be somewhat more expense - a failed 'booter' is possible but not likely.

As for irritating other drivers... this would only occur if the 'aim' was bad or the automatic levelling system is maladjusted or broken. There is a sensor on the back suspension which 'levels' the headlights' aim in situations where you have a heavier load in the back - seat or cargo area. While other 'standard' cars with HID headlights sometimes have two HID bulbs (one for low beam, another for high beam), the Prius uses only one bulb per headlight and actually 'shades' the upper part of the beam for low-beam driving... an unusual but effective approach. Oncoming cars with HIDs can be irritation when there are bumps or sways in the street surface... the top of the HID pattern is a quite sharp cutoff different from Halogens, so when the nose of the oncoming car sways up and down with the HIDs on low beam, the sharp cutoff of the upper pattern moves up so the brighter beam irratates oncoming traffic. I've never been 'flashed' by oncoming traffic with my '07 Prius HIDs.

You will note that when you first turn the HIDs on, there is an instant 'flash' brighter while the gas in the bulb heats up, like perhaps 1 second but noticeable.

I do much prefer the HIDs because their illumination is brighter, more bluish like sunlight and the illumination pattern is wider thus lighting the curbs, adjacent traffic lane and highway 'side lines' noticeably better.

CIAO, Charles

<div class='quotetop'>QUOTE(Charles Suitt @ May 14 2007, 10:17 AM) [snapback]441696[/snapback]</div>

THANKS very much, Charles, will copy/send to my boyfriend.
appreciate the info.
best,

Take that 3000 hours with a grain of salt- HID lifetimes are rated in hours until half-brightness, so it takes 3000 hours until the output is half-as bright as rated, but half brightness may be too dim to drive safely, so the effective lifetime is actually somewhat shorter than that.. How much shorter? Well, it depends on the user's perception- what one person finds too dim might be perfectly acceptable to another..

We have big 500W HID bulbs for our riding arena, and these have a rated life of 25000 hours.. I estimate we put on about 3000-3500 hours yearly (mostly off during the summer, on virtually all day in winter months), and we have to replace them every 2 years or so, as they get progressively dimmer as they age...

Another thing you should be worried about is if you live in New York or areas with high crime: Thieves steal HID lights.

Both of my HID bulbs lasted exactly 14 months. An Orlando FL dealer quoted me $350 each. If this short lamp life continues to be the case, that kind of negates the fuel economy savings, doesn't it?

That sucks. No HID for me then.

I'm past the 14 months and still burning bright!

14 months is an extreme fluke. I know people that have cars with HID lights working on 10 years plus on the same bulbs.

<div class='quotetop'>QUOTE(SW03ES @ May 15 2007, 08:46 PM) [snapback]443075[/snapback]</div>

Mine must be flukey, too. Just lost the first one at 16 months!

do not use them as DRLs. that shortens their life quite a bit.

<div class='quotetop'>QUOTE(galaxee @ Jul 26 2007, 10:53 AM) [snapback]485407[/snapback]</div>

Take it from me... I just learned this lesson the hard way... Don't do it :lol:

<div class='quotetop'>QUOTE(galaxee @ Jul 26 2007, 09:53 AM) [snapback]485407[/snapback]</div>

What is a DRL?

<div class='quotetop'>QUOTE(Zoozoo3 @ Jul 26 2007, 11:50 PM) [snapback]485974[/snapback]</div>

Daytime Running Lights

<div class='quotetop'>QUOTE(galaxee @ Jul 26 2007, 10:53 AM) [snapback]485407[/snapback]</div>

I imagine this is the likely the main reason why HIDs are not offered on Canadian models, since DRL is mandated by law since ~ 1990. Instead, we get 'Auto' halogen headlights on our Prii... :mellow:

<div class='quotetop'>QUOTE(Sarge @ Jul 27 2007, 01:44 PM) [snapback]486203[/snapback]</div>

yep. mutually exclusive for a reason.

OK I do use them as DRL....bad idea I guess. I'm having a hell of a time with my headlights now.
I saw a post a while back that tells how to turn on the fog lights independent of the headlights....anyone know where that is?

<div class='quotetop'>QUOTE(AlphaTeam @ Jul 30 2007, 08:57 AM) [snapback]487370[/snapback]</div>

There are good instructions by darelldd here