7 replies to this topic

[wile e coyote]

Have been raiding the jealously garded Dad's spares stash as I knew some nice aux lighting lurked somewhere - found this little lot and want to fit a pair of driving lamps to my car - they're all Lucas FT/LR's - but what's a fog light and what's a driving lamp out of this lot - 4 on the right or pair on the left?

 

 

 

p.s just in case - yes I'm only proposing to use a pair - but regret none available  - although I know full well they'll return to store - more than my life's worth!!!

 

 

[CityEPete]

I think the left ones with the ribs are fog? Clear ones are 'spot' lights?

[CityEPete]

http://www.s-v-c.co....t/575-lens-fog/

[Cooperman]

Foglights are pretty useless these days as we get very little fog (defined, I believe, as visibility less than 200 yards). Foglights have a short range flat and wide beam to cut under the fog and reduce back-glare. The true idea is that they are used with all other forward lights switched of, except sidelights.

Driving lights are intermediate range, usually just a bit further than normal main-beam headlights, whilst spot-lights give a very long pencil thin beam to pick out objects beyond the range of normal main-beams.

For road use best choice is a pair of driving lights wired to come on when main-beam is selected. From memory I believe the centre height of driving lights has to be a minimum of 16" above road level.

In the photo the foglights are the ones on the left and the ones with some light fluting on the lenses are driving lights. The ones with the plainest lenses are the spotlights.

[CityEPete]

It looks like all four on the right are actually the same, driving lights as Cooperman says, do the 'spots' always have the nipple in the centre?

[wile e coyote]

Excellent - thanks folks! best pair duly purloined remainder about to  return under cover of darkness.... other embargoed items on my list - while the cats away the mouse will go "shopping".....a decent single malt should cover it.....

[Magneto]

I've found fog lights to be useful in all kinds of reduced visibility conditions, including rain and snow as well as good ol fog.

 

Just don't be like the mouth breathers over here and run them all the time...even in bright daylight!

[Cooperman]

Fog lights are useful when the visibility is very poor and less than the range of the headlights on dip beam. Modern dip beams have a better cut-off than the old Lucas units, so fog lights are pretty useless now unless used instead of dipped headlights in very poor visibility when the need is to see the side of the road and the centre line and when the dipped headlights throw back too much glare. This is, indeed, very rare now, but I can still remember the old 'pea-soupers' of smog in the 1960's when even with dipped headlights the side of the road could not be seen. Typically, when using fog lights, the sped of the vehicle should not be more than about 20 mph. If you can drive safely, even in the bad visibility, at over 20 mph then dipped headlights would be OK and fog lights useless.

I can recall having to drive on just a pair of fog-lights in 2nd gear for several miles to get home with the headlights switched of and even the dash lights switched off to reduce the glare. Not much fun! But that was in around 1963 in my 850 Mini which had a pair of fog-lights (and a single centre-mounted long range Lucas SLR700 spotlight). Even the dipped headlights were useless and just threw the light back at the screen.

On rally cars angled fog-lights used to be useful to see small junctions on either side when hurrying on very narrow tracks on the typical road rallies of days long gone.

As an aside, I had a friend who used to say that if one used full beam and spotlights in thick fog and wore poleroid sun-glasses one could see much better. I was never convinced   .