FOAK: Fog Lamps or not on cars.

This new little Clio thingy we have has two 'sockets' for lights on the
front bumper.
Karen has trouble driving in the dark, or twilight times.

So I figured that we could get the lower lamps fitted to give her that
extra bit of light to see if it made any difference.

Anyway, the chap in the Renault garage said it would be illegal to have
them on all the time as they are fog lights.

But what makes a front light a fog light? I can understand the rear
light business. But when is a headlight a headlight and not a foglight
etc.

Anyone know?
Janitors? MOT nerds?

 

The Construction and Use Regs dictate. A foglight is defined in these
by its position - a rule of thumb is that if the light is at or below
bumper level, it is a foglight (although there was a Fiesta that had
driving lights mounted with foglights in the chin spoiler).

The lens and diffraction pattern for a foglight gives a broad spread
of not very bright light over a wide arc, with a sharp cutoff which is
designed to minimise the amount of light bounced back by the fog at
the driver.

It is only permitted to use fog lights in conditions of falling snow
or severely reduced visibility (not darkness) of, iirc 50m. That
doesn't stop the Corsa boys, nor the BMW yuppies, mind.

 

For lamp has a low aim to illuminate the road surface in foggy
conditions. Usually wired so they can be switched on with anything from
sidelights through dip and main beam. They're illegal to use in anything
other than 'restricted' visibility.

What you want are lights that would commonly be known as 'driving
lights' - these have a higher aim, similar to that of your main beam,
and can only come on with the main beam. Not had a car with them for a
while, but I had them on my shite old Escort (although they were mounted
above, rather than below the bumper) - and they had the ability to turn
night into day.

 

SteveH left a note on my windscreen which said:

My VW Passat has fog lights in the main headlight cluster. Would these
be more accuratly described as 'driving lights' then?

 

I don't think he does, see. Mrs Moose wants to be able to see better
on her commute, I guess, where use of main beam would be unwelcome.

 

No. VW are a little odd in this respect. A MkI / MkII Golf can have fogs
mounted in the grille next to the headlamps.

 

If they come on with dipped lights (and go off with full beam) then they're
fog lights. If they stay on with full beam, or come on only with full
beam, they're driving lights.

FWIW very few modern vehicles (AFAIK) have driving lights.
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They do, however, provide a highly visible indication of "**** behind the
wheel". Which is nice.

Soy.

 

I find they dazzle as well as providing the above indication.
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Incorrect. Most (all?) standard fitment foglights stay on with the
main beam as well.

 

[car front fog lights]

Indeed they seem to - which doesn't indicate that they are a) aligned
correctly or b) fulfil their designed function.

 

Erm, are you really sure about that?

No car I've ever own or seen has had front fogs that stay on with main
beam. Apart from anything else, it's a bit pointless. You won't be using
full beam in fog, and if it's not foggy, they should not be on.

However I could be (and probably am) wrong.
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Not necessarily true. Depending on the car's normal lights, there may
be occasions where the extra close-up spread of the fog lights is
helpful even with main beam. And consider all the different causes of
poor visibility - they don't all cause massive reflection back at the
driver.

Apart from very heavy rain and spray, sleet, snow, smoke etc.

Pus many (French) drivers like to leave them on at all times, so I've
had plenty of opportunity to observe.

Well I can say with 100% certainty that Volvo and Peugeot (current
cars) fogs stay on with main, perhaps 99.5% sure of BMW & Jaguar,
going down to perhaps 99.0% confidence for Rover, Vauxhall and Ford.

 

Not in the UK matey, the rules are 'Falling snow and fog that reduces
visibility to less than 50 mtres". Not rain, drizzle, artichoke
invasion or posing down the pub cos it looks cool.

 

No good quoting rules to me mate. you're not seriously going to claim
that nobody uses their fog lights in heavy rain or sleet (which could
perhaps tachnically be called snow anyway) are you?

My point was simply that there may be times when one would want the
fog lights on as well as the main beam.

 

No - there are plenty of examples of people who use them inapropriately.

I can't think of any.

 

Really? You must have a very limited imagination then.

 

Bob left a note on my windscreen which said:

My VW Passat has it's 'fog lights' in the main headlight cluster - above
the bumper and the same height as the headlights and main beam.

So are these fog lights and is it illegal to use them in 'normal'
weather conditions?

 

Why would I want to use a set of lights that dazzle other road users
and offer only a low level of illumination when I have correctly
adjusted headlights and driving lights to use?

 

Because fog lights shine in places that headlights and 'driving
lights' don't. Didn't you read what I wrote up there^? foglights can
give significantly improved visibility of the road edges immediately
in fron of the vehicle, which is a great help in poor visibility, even
if you've got main beam on.

What point, exactly, are you trying to make? So far you seem
determined to disagree on principle, which is fine, of course, but it
might be nice to know what you're wanting to prove.