Way to make fog lights come on auto with headlights?

[BetaDnB]

Originally Posted by Altis

Fog lights are supposed to be brighter to oncoming drivers than your lowbeams...

Can you explain how this works, especially on our cars, with the fog lights being the same bulbs and wattage as the low beams with the fog lights lower to the ground and not projecting as far?

[Altis]

Originally Posted by alfack

Really, a few feet? Any additional reaction time is a bonus.

Quite debatable. It's far, far safer to be focusing your eyes several seconds ahead. You should not be paying attention to the ditches at 60 degrees to the direction of travel at high speeds. That takes your eyes too far from center. You can do something about deer (and other obstacles) that are greater than 1 second away, so it's better to be looking more forwards.

Originally Posted by alfack

Using your high beams in the fog is what is useless. You've never seen the reflection of critter eyes on the side of the road? If your foglights are aimed properly, you are not adding any additional glare to oncoming drivers.

I didn't recommend using your high beams in fog... of course that would be silly. From your post, which recommends using them on a clear dark night in the countryside, that's the part I don't think IS necessarily any safer. Your low beams are located higher and pointed down, which is why they illuminate the road so nicely without too much glare to oncoming drivers. Now, fog lights are located much lower, and are pointed out more. In fact, they don't really have a cutoff.. they're more like flashlights. At best, they provide similar glare as your lowbeams do... but in more cases, they will appear a bit brighter. This is the desired result when driving in fog, as you are visible from a greater distance, without having your high beams light up all the moisture so you can't see a thing!

Originally Posted by alfack

I live in a place with heavy fog and know exactly what they are for; lighting up more of the road. How can more light on the road be bad in any situation?

More light isn't always good. In the country, people don't pass oncoming cars as often say as in the city... so they're eyes might well be adjusted for the dark. You don't want them to have to divert their eyes too much because off additional and unnecessary light in their eyes. More light is bad in tons of situations... imagine if everyone had that mentality and drove around with their high beams on, because more is better? Better yet, go look at all the HID threads and read about why that isn't a "safe" idea.

In fact, the glare of having useless but more bright light right in front of you adds glare to your own eyes, which reduces your viewing distance. If there is any moisture on the windshield, as well, this will be illuminated because of the angle on incidence with the light the fog lights put on the road, so near the front of the car.

Anyways, I'm not even saying don't use them.. I really don't care, lots of people use them. I'm just saying they won't make things safer for you or others on the road. And to tie this back to the original topic, that's why the fog lights are always off by default.

[Altis]

Originally Posted by BetaDnB

Can you explain how this works, especially on our cars, with the fog lights being the same bulbs and wattage as the low beams with the fog lights lower to the ground and not projecting as far?

See above post... it's the way they're pointed (or not aimed at all, really) that makes them appear as bright or brighter than low beams, which are pointed down at the road from a higher point on the car.

That is, in fact, the intended purpose. In fog, you want to be seen from a greater distance, but the high beams are located high on the vehicle and are too bright, so they light up all the fog so you can't see for your life!

[BetaDnB]

Directional light is brighter than omni directional light.

[Altis]

Originally Posted by BetaDnB

Directional light is brighter than omni directional light.

Neither light is omnidirectional... they're both in reflector housings. The difference is low beams are pointed down, intentionally away from oncoming drivers. Fog lights aren't really pointed at all, and the result is more light in the entire upper range and to the sides a bit. Good for having others see you.

[alfack]

Originally Posted by Altis

so they're eyes might well be adjusted for the dark. You don't want them to have to divert their eyes too much because off additional and unnecessary light in their eyes.

Again, if they are aimed properly, i.e. not pointing up, there is no additional light in oncoming drivers' eyes.

More light is bad in tons of situations... imagine if everyone had that mentality and drove around with their high beams on, because more is better? Better yet, go look at all the HID threads and read about why that isn't a "safe" idea.

Give me a break. If you are driving and alone on the road, more light on the road is always better, unless you are trying to cut down on the number of bug splats! Like driving in daylight. My mentality does not include HID hack job kiddies that don't know how to aim their headlights and go around blinding people.

Anyways, I'm not even saying don't use them.. I really don't care, lots of people use them. I'm just saying they won't make things safer for you or others on the road. And to tie this back to the original topic, that's why the fog lights are always off by default.

They can definitetly make things safer for yourself driving at night. They are not intended to make it safer for others.

[pozi240]

Don't bother arguing with Altis, he clearly is much smarter than us and is well versed in how fog lights are designed and how they are enginereed to work. LOL. It's no surprise you're from Ottawa, I lived and worked there for 3 years very recently and this attitude from its driver's was VERY prevalent. (To be fair, there is a LOT of diplomatic "red plated" drivers their that have no business on the road). Some of your answer's about night time visibility and fog lead to believe you truly don't have a clue how to drive in heavy fog at night or otherwise. Oh yeah, that's right, Ottawa is the "fog capital" of Canada... wait, it's not... LOL. We wouldn't have any idea about fog out here living on the Atlantic coast (or any of our southern neigbhors along the eastern seaboard)...... It's clear you don't like fog lights or oncoming cars that have them on (I do agree that a LOT of cars with OEM fogs are barely effective), but, they are definately NOT brighter than low beams and do not "dazzle" oncoming traffic, since they are actually aimed LOWER than your low beams and not (by definition and design) directional (driving lights, conversely are directional). Anything that is aimed high (as in low beams or high beam headlights) or very bright will simply "bounce" back off of heavy fog and make it nearly impossible to see where you're driving. Fog lights are indeed pointed, but, since they are NOT a directional beam pattern, they appear to scatter, but, that light output is scattered to the sides of the car and the ground directly in front. If you want to test this, wait until dark, go to a deserted road, turn on your low beams and fog lights, park car on level surface and walk about 20 feet or so in front. Now, crouch down until the low beams are hitting you in the face, notice that the fogs still are NOT hitting your eyes yet? You will have to crouch even further downward (almost laying on the ground) until you "see" the beams from the fogs hitting your face. Now, an oncoming car's driver will be sitting MUCH higher up for the fogs to "bother" them, not to mention, they are not nearly as bright (yes, I know they use the same H11LL bulb), due to the non directional reflector as opposed to the low beams concentrated beam pattern. Still not convinced Altis? Go find a white wall (underground parking garage for example) somewhere,turn on all of your lights and back away slowly, you will see just how "low" the beam pattern of the fog lights really are. You certainly are entitled to your opinion, and clearly you don't like fog lights (for whatever reason), but, to say they are not helpfull to seeing or to safety is a callous statement.

[Altis]

Originally Posted by alfack

Again, if they are aimed properly, i.e. not pointing up, there is no additional light in oncoming drivers' eyes.

Again, they aren't directional lights really... so aiming them isn't exactly an effective option. In any case, that also defeats the purpose a bit.

Originally Posted by alfack

Give me a break. If you are driving and alone on the road, more light on the road is always better......[snip]..... They can definitetly make things safer for yourself driving at night. They are not intended to make it safer for others.

If it's not foggy, wouldn't your high beams be the better choice for night driving on country roads? You have yet to dispute the points I made about extra glare. "more light on the road is always better" is not a true statement, as I've shown. They increase glare for you and all oncoming drivers, while illuminating a useless portion of the road that you should not be focused on while driving at speed. This is why it's illegal to use them outside of poor visibility conditions in many areas, such as the UK.

A quick google search returned this...
http://uk.answers.yahoo.com/question...6153116AAUFtd0
http://www.letstalkdriving.co.uk/USE...G%20LIGHTS.htm

High beams are far, far more effective when driving alone at night and I would highly recommend you use those on country roads instead. If it's foggy, go ahead and use your fog lights instead and drive a bit slower.

And for hypermilers, you burn an extra 0.02 gal of fuel per hour while using them.

[FZJ80]

Originally Posted by Altis

I don't understand how illuminating the first 6 feet in front of the car brighter helps at all when driving at 80 ft/second. It just adds more glare to oncoming drivers, reducing safety.

Fog lights are supposed to be brighter to oncoming drivers than your lowbeams... which is why by default, they're always off. So if you want them on, turn them on.

If they are illuminating the first 6 feet in front of the car, why would they be brighter than the your low beams to oncoming drivers? That doesn't make any sense.

Originally Posted by alfack

You have it all wrong. Foglights are not supposed to be brighter to oncoming drivers than low beams. They are supposed to illuminate the gap between the front of your car and where your low beams start. They are also supposed to illuminate the sides of the roads.

Bingo!

Originally Posted by Altis

What's the point in lighting up the first few feet of the road? You're going way too fast to be able to do anything about those first few feet. On many cars with fog lights, you can't actually tell whether or not they're on from inside the car.

As alfack stated, A true fog light is supposed to light up the area directly in front of the car. And as Altis stated, you are going way too fast to react to anything in that space. So what is the point of a fog light?

Fog lights are supposed to be used with the low beams turned off, when you are travelling in fog that is so thick you can't see your hand in front of your face, and therefore are going about 5mph. This has happened to me twice, once in a older car with aftermarket fog lights that I could turn on independently of my headlights, and once in a newer car with factory "fog" lights. Man, was I pissed I could not turn off my headlights to reduce the glare of the fog. It is damn scary to be on a highway when the fog (or snow) is so thick you can't see the lines on the road. At least once every winter, somewhere in the US there is a case of people being killed in these low visibility situations.

The government has mandated that we can't use fog lights as the only source of illumination, and that's probably a good thing because stupid people would be driving around with only their fog lights on and getting into accidents because they can only see 20 feet in front of the car. However, it would be nice if we could figure out a way to override the safety mechanism so that those of us who know what we are doing could use these lights for their long forgotten intended purpose.

[Altis]

Originally Posted by FZJ80

If they are illuminating the first 6 feet in front of the car, why would they be brighter than the your low beams to oncoming drivers? That doesn't make any sense.

Because they're not aimed, whereas the low beams specifically point down from a higher point. A lower light with a very ominous projection will still light the road.... and the sides, and ahead, and above, etc etc.

Originally Posted by FZJ80

However, it would be nice if we could figure out a way to override the safety mechanism so that those of us who know what we are doing could use these lights for their long forgotten intended purpose.

Not sure what safety mechanism you're talking about. Having them not be off by default? Because you already can drive with just the corner lights and fogs, even on cars with DRLs.. if that's what you meant.

Anyways,l this clearly isn't going to get us anywhere.

My whole point about this was simply that many cars intended for the rest of the world have it such that the fog lights will always be off when you start the car. There are many places around the world where it is in fact unlawful to drive with them on when visibility is clear.

You can argue with me all you want, but the fact that it is specifically illegal to use fog lights in many countries in clear nights means that traffic authorities know that they are certainly not more safe to use in such conditions.

I do agree that most people don't use things the way they are intended... but that's what I think the majority of people are trying to do. The only reason people are concerned about having them be on every single time the headlights come on is because they don't want to have to determine if they need them... they just want them always on.

Additional Info: UK Gov Highway Act.. http://www.direct.gov.uk/en/TravelAn...code/DG_069859

Note 226 and 236.