Fog or Driving lamps

To drive in fog. Fog lamps. Obvious innnit? They should be seet low to "cut under" the fog. They don't give you mystical powers but they help a great deal on cars I've had that have had them. They let you see that little bit further IME.

"gazzafield" wrote in message news:tq-dnWKjA snipped-for-privacy@pipex.net...

OK OK i know that but if you have Headlamps what are driving lamps for ?

Do you have one Fog and a spot or two fog's

Dipped headlights are near the plane that your eyes are. The light reflects back into your eyes from the water droplets. That is why it is often possible (though both dangerous and illegal) to see further in daylight fog by driving on sidelights only.

The principle of foglights is that because they are mounted much lower than headlights, the angle between the light source, the reflective water droplets and your eyes is greater. This reduces the effect of your own lights dazzling you; much of the reflected light passes above the vehicle.

Properly designed and carefully set up fog lights can help a little when the fog is moderate to heavy. Sadly, the ones fitted by manufacturers rarely meet those criteria. In some cases, they can only be switched on *with* dipped headlights, making them completely worthless!

Unless you live in an area prone to fog, for example near the coast, I would suggest foglights are not necessary. Whatever, you do need to slow down in foggy conditions, and probably more than most of us do.

So-called "driving lamps" belong on a chav's Corsa, where they will soon be smashed in the inevitable crash. Oh, and they will make your ability to see in the fog worse, rather than better.

Chris

What used to be known as spotlights AIUI. So they're to blind other drivers and serve no other useful purpose unless you are a rally driver or are about to set off to Outer Mongolia.

Any car that has had them has always had two fogs and no "driving lamps".

Hide quoted text -

My understanding is that fog lights,

Are to be used purely as a fashion item, in weather conditions, where lights are not required.

Is this not true.

Fog lamps are positioned low and have a flat topped beam designed to 'cut under' the fog and only illuminate a few feet in front of the car - without glare back to the driver from reflection off the fog. And are only suitable for very low speeds - like those sensible in thick fog or a heavy snow fall.

Driving lamps are simply an additional main beam.

My driving lamps make an increadible difference to wide angle viewing - the headlights give long distance straight light, the driving lamps light up the kerbs, the white lines better, things in the hedge and on the pavements.

...and the oncoming vehicles, their drivers, and the whites of their eyes glow very nicely too!

No, because you're not meant to use them with anything other than full-beam headlights. :)