High beam as DRL... the logic escapes me.

[Unicorn]

I understand the use of the high beam as it's not used very often so it's life being shortened is not a big consequence, especially on a dual filament bulb. I've never had the high beam go out except with separate bulbs. That part I get.

What I don't get is the use of any headlight as a DRL. They don't have the correct t beam pattern right? I've seen that posted here in response to why just turning your lights on isn't a great idea. So how can just having slightly dimmer high beams be very effective? Surely not as effective as separate, purpose designed DRLs? Cost savings by the auto makers since they are optional in the US, and the standard is pretty lax?

 

[Alaric Darconville]

What I don't get is the use of any headlight as a DRL. They don't have the correct t beam pattern right?

But they do. If they didn't, they wouldn't be permitted as DRLs, would they? Granted, there can be problems with such implementations of DRLs (potential for glare, potential to not be interpreted properly, potential for masking turn signals), but essentially a legal DRL is a legal DRL is a legal DRL.

Also, DRLs are required in Canada on cars model year 1990 and newer. Doing it effectively, and cheaply, led to (reduced power) high beam or low beam DRLs. Canada allows fog lamps as DRLs, we don't here. So at least we got THAT going for us

The automakers have fought more stringent requirements, eventually resulting in more or less acceptable DRLs based on modifications of the existing lamps' functions.

Part of the answer, then, is money.

 

[Unicorn]

So basically it's justt good enough to meet a very lax standard of something is better than nothing.

 

[-Virgil-]

High-beam DRLs are cheap to implement (existing lamps) and cheap to cover under warranty (very long bulb life). That's why the auto industry bucked hard (and successfully) to get them permitted back in the late '80s when Canada proposed a DRL specification very much like the one that's been required in Europe since 2011 -- functionally dedicated DRLs emitting no more than 1500 candela. That's a better DRL, but also a more expensive one.

 

[270winchester]

Those with 97-99 Camry's will know the draw backs of having your low beam at reduced power as DRL with no off option unless you unplug the drl plug.

Urgh.

 

[-Virgil-]

What drawbacks do you have in mind?

 

[Unicorn]

I can think of some for any DRL, but those have been brou g t up ar.eady in other threads. Entering secured areas and not blinding the guard at the gate.
They'll also burn out more quickly because they're on more often. I can see that being a reason for using the high beams but with a lower output. Those aren't used nearly as much so lifespan isn't à big problem.

 

[-Virgil-]

I can think of some o any DRL,

Such as...what? It sounds like you're opposed to DRLs no matter how they're implemented? How come?

Entering secured areas and not blinding the guard at the gate.

Not only do reduced-intensity low beams not glare whoever you're driving towards, but such a secure-area entry scenario is a very infrequent occurrence, easily solvable with a temporary-override switch -- there are already provisions in the reg for such a switch (to turn off the DRLs until the vehicle exceeds some particular low speed or travels more than some particular number of feet after the switch has been pressed). If this secure-area-approach were a good reason to object to any kind of DRLs, it would apply to high beam DRLs, not low.

They'll also burn out more quickly because they're on more often.

Remember, small reductions in bulb voltage mean very large increases is bulb lifespan. The exponent is -13 (that's negative 13), so reducing the voltage to the low beams by 10% increases the lifespan of the bulb to about four times its rated lifespan (relative to full-voltage operation). So in DRL mode, the low beam bulbs will make progress toward their eventual burnout, but at a very slow rate.

 

[Unicorn]

I don't see a reason for using the headlights for DRLS at all. A dedicated, separate assembly makes the most sense.
Headlights don't have the proper beam, but are ok if they are just dimmer? During the day when is light out regular headlights are to glaring... as I believe sorbet you or Alaric have stated, yet at night they are ok and won't cause problems for other drivers. There was that thread recently asking why not just turn your headlights on, and the answers given seemed to a that headlights were the wrong lights.
Your words,

Really, it's a question of the optimal tool for the job. The headlamps can function as DRLs, but that's not really what they're designed for so they don't do an optimal job of it. Functionally-dedicated DRLs, if properly implemented, can do a better job than turning on the headlamps.

Full-intensity high beams are far too bright to use as DRLs, and many low beams don't produce a beam distribution that is optimal for the daytime conspicuity job. Also, dedicated DRLs are much more cost-effective because almost all varieties of them use much less energy and have much longer bulb lifespan than the headlamps.

If a full power low beam doesn't produce optimal beam distribution, having it at 70% (made up number) isn't going to change that.
Then you started a longer life of a dedicated DRL.
So basically I agreed with everything you put in that paragraph, yet I'm wrong?

Entering secure areas is not infrequent if you're in the military, work on a military post or at one of the many government installations in the DC or several other areas.

 

[-Virgil-]

I don't see a reason for using the headlights for DRLS at all.

It's cheaper to add to the vehicle and (in some cases) to the vehicle warranty than adding a dedicated DRL, and it's legal in North America. It's really that simple.

A dedicated, separate assembly makes the most sense.

A functionally-dedicated DRL (whether it's a separate assembly or built into other lighting clusters) is functionally the best, but also costs more, so saying it "makes the most sense" isn't strictly correct. The automaker's cost-control personnel have a different idea of "makes the most sense" than the safety and design personnel.

Headlights don't have the proper beam, but are ok if they are just dimmer?

Yeah, it's a conundrum however you look at it. Headlight DRLs really are not a best practice, but they are legally accepted.

If a full power low beam doesn't produce optimal beam distribution, having it at 70% (made up number) isn't going to change that.

You're right, it's going to aggravate it!

So basically I agreed with everything you put in that paragraph, yet I'm wrong?

Whether you're right or wrong depends on what question you're answering. Big general questions or statements like "headlight DRLs are bad" aren't worth discussing, because they're unrealistically broad and categorical. The real world doesn't often work according to binary good/bad, yes/no, black/white choices. Headlight DRLs are functionally suboptimal, but economically favorable for the automaker.

Entering secure areas is not infrequent if you're in the military, work on a military post or at one of the many government installations in the DC or several other areas.

Most people don't enter secure areas most of the time.

 

[Alaric Darconville]

Entering secure areas is not infrequent if you're in the military, work on a military post or at one of the many government installations in the DC or several other areas.

I've noticed in some of the State vehicles I've driven lately, they have a way to turn off the lights for such things like approaching the drive through or a military installation-- the Traverse is one example with that.

I guess that helps ensure they get the government contracts-- their vehicles comply with such policies. It's almost as if they have a guy on the inside...

They also have foot-operated parking brakes, but I think I'm the only one that ever uses it. I'm waiting for someone to complain and me get griped out because the other users drive off with the brake still on.

 

[270winchester]

What drawbacks do you have in mind?

-the lack of option to turn it off completely in those particular model years from a driving position.

-when you use high performance bulbs like xtreme vision, etc, the light being constantly on, no matter how much easier the reduced voltage is on the bulb, reduces overall service life for when I need the light, and when it's an H4 set up, lower filament burn out = whole bulb has to be thrown out

-when you add a wiring harness, the light then would burn at full brightness due to the original wiring acting only as a signal, so any current tells the relay to turn full on.

I noticed on the next generation (02+) Camrys the DRL-off option was added back, so clearly the 97-99 set up was not universally liked.

 

[-Virgil-]

-the lack of option to turn it off completely in those particular model years from a driving position.

That is true. It's a safety item. Most of them don't have overrides. We can't selectively disable the left rear turn signal, the CHMSL, the right front side marker light (or, for that matter, the left front brake) from a driving position. DRLs are different in that the regulations provide for a temporary override switch reachable from the driving position. Few makers offer such a switch, but that's not a choice being forced on them by anyone.

when you use high performance bulbs like xtreme vision, etc, the light being constantly on, no matter how much easier the reduced voltage is on the bulb, reduces overall service life for when I need the light

Fair enough: any operation of the bulb, even at reduced voltage, will mean the "meter is running" on its lifetime. But DRLs really do reduce your likelihood of being in a crash, so the bulb lifetime used by DRLs isn't wasted. I don't think objecting to DRLs on this basis makes a lot of sense, for the same reason I don't avoid using my brakes so as to avoid "reducing overall service life" of the brake pads.

and when it's an H4 set up, lower filament burn out = whole bulb has to be thrown out

That's the case with or without DRLs.

when you add a wiring harness, the light then would burn at full brightness due to the original wiring acting only as a signal, so any current tells the relay to turn full on.

That would go under the category of "stupid owner tricks", i.e., ill-advised, incorrectly done vehicle modifications that result in an illegal/noncompliant, unsafe situation.

 

[270winchester]

That is true. It's a safety item. Most of them don't have overrides. We can't selectively disable the left rear turn signal, the CHMSL, the right front side marker light (or, for that matter, the left front brake) from a driving position. DRLs are different in that the regulations provide for a temporary override switch reachable from the driving position. Few makers offer such a switch, but that's not a choice being forced on them by anyone.

I'm confused about this statement. We have late model year cars from Toyota, Ford and Chrysler, and all of them have a DRL-off option on the light switch.

That's the case with or without DRLs.

and having your low filament on whenever the car is in motion certainly doesn't help.

That would go under the category of "stupid owner tricks", i.e., ill-advised, incorrectly done vehicle modifications that result in an illegal/noncompliant, unsafe situation.

Then Daniel Stern must be the most obnoxious illegal equipment pusher out there for selling relay kits and helping people with making better wiring for their headlights.

In what way is not having DRL illegal/non-compliant in the US?

 

[Alaric Darconville]

Then Daniel Stern must be the most obnoxious illegal equipment pusher out there for selling relay kits and helping people with making better wiring for their headlights.

Stern will ask people what vehicle they're modifying, and if a problem could arise (accidental activation of high beam DRLs at full voltage due to the relays), he can provide workarounds, such as the DRL-1 to move DRL function to front turn signals.

In what way is not having DRL illegal/non-compliant in the US?

Not having a compliant DRL is what makes it non-compliant in the U.S. If a high beam lamp is used as a DRL, it should run at a particular maximum intensity. It's legal to not have the DRL *at all*, but if it's there, it must function correctly.

 

[270winchester]

Not having a compliant DRL is what makes it non-compliant in the U.S. If a high or low beam lamp is used as a DRL, it should run at a particular maximum intensity. It's legal to not have the DRL *at all*, but if it's there, it must function correctly.

Is the usage of existing DRLs mandated by state level vehicle codes? I don't remember seeing it in the CA CVC, but I could have missed it. Or are you talking about a high or low beam running at full brightness due to relay kits as the non-compliant part?

 

[-Virgil-]

I'm confused about this statement. We have late model year cars from Toyota, Ford and Chrysler, and all of them have a DRL-off option on the light switch.

What's confusing? It should not be terribly difficult to understand that many vehicles do not have such an option. But it is interesting to note that other makers are following Toyota's lead and offering DRL temporary-off switches.

Then Daniel Stern must be the most obnoxious illegal equipment pusher out there for selling relay kits and helping people with making better wiring for their headlights.

I haven't seen Stern advocate improper use of relays or improper hookup of DRLs...have you? All cars are equipped with lamps that are dangerous when misused -- all it takes is the driver using high beams in traffic. By the logic(?) in your indictment of Stern, then, the glare danger resulting from use of high beams in traffic would be the automaker's fault. That makes no sense.

In what way is not having DRL illegal/non-compliant in the US?

DRLs are not required in the United States (nobody has said otherwise). However, if DRLs are present on a vehicle, they must comply with the design, construction, installation, and performance requirements contained in FMVSS 108.

270Winchester, the way you retroactively change questions after they've been answered in order to debate what had been a cogent answer is beginning to make it seem your goal in this thread is mostly to argue. Please take a more mature tone and attitude or the thread will be closed.

 

[Alaric Darconville]

Is the usage of existing DRLs mandated by state level vehicle codes? I don't remember seeing it in the CA CVC, but I could have missed it.

I'm pretty sure it's not. The States certainly can't require a car to be equipped with lights that are NOT required by Federal law.

DRLs are Federally-regulated, but not required. They subsequently are permitted under State laws.
However, if they are present, they must work correctly per the Federal regulations, meaning no high-beam DRLs wherein the high beam is at full intensity.

 

[270winchester]

DRLs are not required in the United States (nobody has said otherwise). However, if DRLs are present on a vehicle, they must comply with the design, construction, installation, and performance requirements contained in FMVSS 108.

270Winchester, the way you retroactively change questions after they've been answered in order to debate what had been a cogent answer is beginning to make it seem your goal in this thread is mostly to argue. Please take a more mature tone and attitude or the thread will be closed.

Not trying to sound argumentative. I am trying to clarify what is the part that was labeled illegal/non-compliant.

If a DRL functionality is present on a vehicle operated in the US, is it illegal to disable the DRL?

 

[270winchester]

I'm pretty sure it's not. The States certainly can't require a car to be equipped with lights that are NOT required by Federal law.

DRLs are Federally-regulated, but not required. They subsequently are permitted under State laws.
However, if they are present, they must work correctly per the Federal regulations, meaning no high-beam DRLs wherein the high beam is at full intensity.

Thanks. I in no way advocate running DRLs over their intended output.