HID Should I turn them off during the day?

I think off is the winning move.

YOMV - your opinion may vary....

 

Off. The safety studies for daytime headlamps have very mixed results. Not only are HID lamps expensive to replace, they also degrade over time, which means your lamps get dimmer and dimmer, long before they burn out, which is also a safety issue. I leave mine off during the day.

Tom

 

But please do use them at dusk and on heavily overcast days when most others have their on. It seems to me that on darker days with heavy overcast of 1/2 hour after sunset, a car with healights off sort of dissapears if it is in a line of cars with their headlights on.

I have stoped using my HID during the day since I heard replacement bulbs run in the hundreds of dollars. Now I really want to rig my fog lights for DRLs.

 

If you want daytime running lights, do the fog light mod and leave your headlights off unless it's dark.

Prius

Go to "mods" then "fog light only mode"


Or:
http://priuschat.com/forums/knowled...b-turning-fog-lights-indepent-headlights.html

 

running them constantly really shortens their life.

 

Thats what sucks about the Canadian Prius you cant get the HID here as an option, i assume they arent recomended to run all the time, you are definatley safer with something on, i dont care what anybody tells you.

 

I really want some DRL of some type, and I have the HID option, so I was seriously considering the Fog light on only mod, but have read in the last couple days and confirmed that this is not permitted in the US. I may do it anyway, as I cannot for the life of me see how they would be worse on other drivers eyes during the day that lower powered high beams.

 

DRL's are ultra important - there are not really 'mixed results' other then some lobby groups.

Every true real-world study has shown that DRL's reduce collision rates and head on accidents by 30%. Check the before and after in Canada or by GM on their stats they ran several years back when they switched over.

Keep the lights on - it's safer - people can see you more.

The nay sayers tried the same arguments in the 1970's when Motorcycles had to have their lights on all them time. In the end, science and statistics prevailed...

 

I use my HID's as DRL's. This is because fog lights are too low (on the vehicle) and actually use more power then the HID's according to this board.

The dealer first programmed my side marker lights to be the DRL's but they were WAY too dim - couldn't see them during the day at all. If you could program the turn-indicators to be your DRL's that would probably work.

Bottom line; please use DRL's and check for yourself on the stats. Car Manufacturers Lie, Stats don't....

 

Here is a link to get started with your reading: Daytime running lamp - Wikipedia, the free encyclopedia

And a brief quote from above to stir things up:

Tom

 

Please don't quote Wiki as science. I could have put up that post yesterday on Wiki.....

Best to quote true reliable sources such as the AAA, CAA or the IIHS - who all say the same thing...........

Q&As: Daytime running lights

 

4 | How effective are DRLs?
Nearly all published reports indicate DRLs reduce multiple-vehicle daytime crashes. Evidence about DRL effects on crashes comes from studies conducted in Scandinavia, Canada, and the United States. A study examining the effect of Norway's DRL law from 1980 to 1990 found a 10 percent decline in daytime multiple-vehicle crashes.1 A Danish study reported a 7 percent reduction in DRL-relevant crashes in the first 15 months after DRL use was required and a 37 percent decline in left-turn crashes.2 In a second study covering 2 years and 9 months of Denmark's law, there was a 6 percent reduction in daytime multiple-vehicle crashes and a 34 percent reduction in left-turn crashes.3 A 1994 Transport Canada study comparing 1990 model year vehicles with DRLs to 1989 vehicles without them found that DRLs reduced relevant daytime multiple-vehicle crashes by 11 percent.4
In the United States, a 1985 Institute study determined that commercial fleet passenger vehicles modified to operate with DRLs were involved in 7 percent fewer daytime multiple-vehicle crashes than similar vehicles without DRLs.5 A small-scale fleet study conducted in the 1960s found an 18 percent lower daytime multiple-vehicle crash rate for DRL-equipped vehicles.6 Multiple-vehicle daytime crashes account for about half of all police-reported crashes in the United States. A 2002 Institute study reported a 3 percent decline in daytime multiple-vehicle crash risk in nine US states concurrent with the introduction of DRLs.7 Federal researchers, using data collected nationwide, concluded that there was a 5 percent decline in daytime, two-vehicle, opposite-direction crashes and a 12 percent decline in fatal crashes with pedestrians and bicyclists.8

 

This will obviously not be something that some of you will not agree with but, I see no difference in the number of people who try/tried to pull out in front of me when driving my '99 Saturn(has DRL's) than my Prius(doesn't have DRL's).

 

Living in Canada you get really used to DRL's. When a car is driving without them we know it's 90% probably someone who drove up from the USA.

You notice the difference the DRL's really make. You know for sure that a car is on when you see their lights. You get so accustomed to them that the few times you see a car without them it's almost like a fear reflex.

One thing I have noticed for sure is that it helps differentiate between cars that are driving and cars that are parked. Your concentration is shifted towards the cars with the headlights on and you 'ignore' the ones on the side of the road better.

It's hard to explain, perhaps Tideland can do a better job.