Automatic headlights constantly on?

[BRZnut]

Originally Posted by Tcoat

Um I don't think so. Not like there are filaments in there that are heating and cooling. I could be wrong though so if anybody can support BRZ (with some form of documentation please) I am curious. I have always left mine on auto on my previous cars and they all were still perfect after 300,000 miles. Can't find a single official statement on the subject.

When I got one of those HID coversion kits a few years ago for my previous car, I did a lot of reading about HIDs. I read in a few places that frequest cycling on and off shorten the HID bulbs life.


Quick search today:



Someone comparing LED to other bulbs:



http://warwickadvertiser.com/apps/pbcs.dll/article?AID=/20140619/EXPERTS05/140619960/Does-frequent-on/off-switching-of-LED-bulbs-shorten-their-life?



Discussion over at Nissan where someone quotes from his manual:



http://www.nissanclub.com/forums/2007-2012-nissan-altima-discussion-2-5-3-5/246541-will-using-auto-headlight-shorten-hid-life.html

[Tcoat]

Originally Posted by BRZnut

When I got one of those HID coversion kits a few years ago for my previous car, I did a lot of reading about HIDs. I read in a few places that frequest cycling on and off shorten the HID bulbs life.


Quick search today:



Someone comparing LED to other bulbs:



http://warwickadvertiser.com/apps/pbcs.dll/article?AID=/20140619/EXPERTS05/140619960/Does-frequent-on/off-switching-of-LED-bulbs-shorten-their-life?



Discussion over at Nissan where someone quotes from his manual:



http://www.nissanclub.com/forums/2007-2012-nissan-altima-discussion-2-5-3-5/246541-will-using-auto-headlight-shorten-hid-life.html

Ya I found both those when I was looking. Still not saying you are wrong but some random dude pushing LEDs and another forum with one guy saying it is a problem doesn't help. There really are no facts out there at all. Hmmm now it is a challenge.


UPDATE
Still a forum but at least it is a lighting one and it is the most "official" thing I could find. The answer is yes turning them on and off rapidly will reduce the life but not by any significant amount. You may get 4.7 years instead of 5 years out of them. So all in all not a major concern over the expected life span of a car.
http://www.candlepowerforums.com/vb/...HID-headlights

[BRZnut]

Maybe a small decrease in life of the HID, but still a concern for me.


It would be great for those of us that keep their cars in a garage, that at start up there could be a delay in the lights going on (just to give us a few min to get out of the garage), or at least having the system keeping track of the time of day at start up to avoid the on-off issue.

[Tcoat]

Originally Posted by BRZnut

Maybe a small decrease in life of the HID, but still a concern for me.


It would be great for those of us that keep their cars in a garage, that at start up there could be a delay in the lights going on (just to give us a few min to get out of the garage), or at least having the system keeping track of the time of day at start up to avoid the on-off issue.

Is there no manual setting so you don't even have to have them on auto (I don't have them on the FRS)? My other cars all had it so they can be auto or just manual.

[Poodles]

Originally Posted by Tcoat

Um I don't think so. Not like there are filaments in there that are heating and cooling. I could be wrong though so if anybody can support BRZ (with some form of documentation please) I am curious. I have always left mine on auto on my previous cars and they all were still perfect after 300,000 miles. Can't find a single official statement on the subject.

Originally Posted by AKUSHOU

I agree with you @Tcoat. Doubtful that it will cause the bulb to fail. HID bulbs produce an electrical arc in the inner glass between the two pieces of metal. If anything the ballast will fail, highly unlikely but possible. OEM HID components go under a lot more quality control practices than aftermarket or knock off companies that produce the same type of HID equipment.

Why do you think they're so many OEM branded fakes being sold on places like Ebay. Unsuspecting customers in the masses and it mostly cheap junk posing like Philips, Osram, Bosch... etc

It has to do with the salts in the bulbs. If not given ~5 minutes of on time to fully heat up, the salts will deposit oddly and effectively be "lost" as they won't turn into a gas again. There is also the issue of the electrodes wearing, which happens on start up.


Also keep in mind, HID bulbs aren't like halogens. Halogens will keep something like 95% of their output right until they fail. HID's will taper off and color shift well before they stop working. (Can't seem to find the graph I had of this, but it's pretty comical how much light is lost)


I know of people that change their HID bulbs yearly because of this loss of light. There's a hell of a lot of early HID cars on the road today that are outputting less light than a cheap halogen and at colors that are difficult to see.

[Tcoat]

Originally Posted by Poodles

It has to do with the salts in the bulbs. If not given ~5 minutes of on time to fully heat up, the salts will deposit oddly and effectively be "lost" as they won't turn into a gas again. There is also the issue of the electrodes wearing, which happens on start up.


Also keep in mind, HID bulbs aren't like halogens. Halogens will keep something like 95% of their output right until they fail. HID's will taper off and color shift well before they stop working. (Can't seem to find the graph I had of this, but it's pretty comical how much light is lost)


I know of people that change their HID bulbs yearly because of this loss of light. There's a hell of a lot of early HID cars on the road today that are outputting less light than a cheap halogen and at colors that are difficult to see.

Ya, my research showed that drop off is a far bigger issue that wearing the electrodes out by frequent on and off. Appears that the drop off happens regardless of how often they are turned on and off. I even saw a chart that was probably the same as you mentioned. It was mentioned several times that the drop off is so gradual that most don't even notice it. So the lights that are rated for 4,000 hours will still work at that point but are not nearly as effectively as they were.
I really never did notice any colour shift in my cars that had them even at a couple of hundred thousand miles but I bet it was there.

[BRZnut]

Originally Posted by Tcoat

Is there no manual setting so you don't even have to have them on auto (I don't have them on the FRS)? My other cars all had it so they can be auto or just manual.

I keep them off and just turn them on when needed (ie use the lights in manual mode). But would be nice to use the auto setting if it was "smarter"!

[Tectoniic]

Originally Posted by BRZnut

I keep them off and just turn them on when needed (ie use the lights in manual mode). But would be nice to use the auto setting if it was "smarter"!

Next big FT86 club debate: Do you use the automatic setting on your lights or do you turn them on/off manually.

Inb4: "Turning the lights on and off manually makes me feel more connected" - "The automatic is far superior to a humans reaction and can turn the lights on/off faster than we can"

That's how these normally go right?