Its all relative and estimated in those studies. Tons of variables to boot (Newer cars had better stopping distances with new brakes/tires/ABS ect ect ect.

Do you really pay more attention to a car because of some dim glow in the headlights? I see cars just fine, government mandates can and have ruined driving experiences.

Its good for dumb asses and drunks that forget to turn their headlights on in shit conditions/night.

And a study that shows they have no effect (unless your driving a small truck apparently):

4. NHTSA’s most recent study finds no significant benefit to daytime running lights. It’s a little hard to track down, but NHTSA technical report HS 811 029 (pdf) states:

This is the third statistical analysis conducted by NHTSA to evaluate the effectiveness of daytime running lights (DRLs)…the analysis found that DRLs have no statistically significant overall effects

NHTSA’s study did find that daytime running lights reduced light truck crashes about 5%, but otherwise they had no statistically significant impact on safety.


That being said I would leave them alone on any car I owned.

On the other hand, it makes it impossible to flash your headlights at those drunken dumbasses to let them know that they forgot to turn their headlights on. ;)

http://www-nrd.nhtsa.dot.gov/Pubs/811029.pdf

The study is pretty easy to find. Reading through it now. Thanks for the link.

Based on this statement (the formula can be found in the pdf) and the table on page viii which shows that the fatal car accidents for cars with DRL is -9.3. This means that cars with DRL actually have a 10% higher likelyhood of killing someone!

Take these out right away!!!! :P


...granted this contradicts the studies in all other 18 countries that currently have DRL laws. :)

I've found that those dumbasses are too stupid to translate the light flashing anyway!

my take on DLR has always been for those cases of dusk and dawn.

when it's light enough for you to just drive the car but since the lights are off you're harder to see for other people.

i also drove a car with shitty lights for so long i don't even know when they are on or off, but for somebody else even a faint glow is warning enough. THere are some dumbass drivers out there that need all the warning they can get.

WTF? The FR-S DRL's operates the high beams at a lower voltage via a resistor?

I though they were a separate light bulb, oh well. Dammit Scion!

?

This is what a lot of cars use, especially Toyotas.

Jeff

OK, so I pulled my DRL fuse today and the DRLs still came on. WTF? I triple-checked that I pulled the right fuse... so I guess I will be pulling that resistor 100%!

Might not pass a state inspection depending on state and on the inspector. since as Longhorn pointed out, it is technically illegal.

They aren't required by law yet are they? If not, then there is no reason to assume it's illegal.

Not sure which fuse you pulled, but there is no "DRL" fuse.

The only fuse that directly affects DRL is the MPX-B fuse, but pulling that wouldn't disable the DRL, it would just prevent you from ever having high-beams.

There are 3 good ways to disable DRL:

1. Remove the resistor, as was shown in this DIY.
2. Replace the DRL relay with a SPST relay that does not have the NC circuit. (4 pin instead of 5 pin).
3. Depin/cut the green wire coming out of the engine fuse box that runs from the engine fuse box to the DRL resistor, or the black wire at the junction near the firewall.

Changing the relay type is the easiest way to go, but costs money. Removing the resistor is harder, but free. Not sure why you'd cut the wire when you've got 2 other choices.

Jeff

After doing a bit more research it looks like it's going to be country dependent. DRL's aren't mandatory in the US, however they are permitted and considered safety devices. I'm fairly certain that removing safety devices on cars is illegal, but couldn't find any actual statutes to back that up. So it may or may not be illegal to disable them, but like I said before, I don't think anyone will have get into trouble for it.