How to use fog lights?

[Xdama]

that defeats the purpose of fog lights and highway code is very clear that you can use foglights with or without dipped beams (the former doesnt quite make sense except on older cars with crappy headlights though)

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These are taken directly off the UK Highway Code website. Note 226 - must use headlights - may use foglights. Car manufacturers have to follow strict guidelines to allow the sale of new vehicles consequently one of those is that foglights are NOT enabled unless dipped beam headlights are switched on. There’s nothing wrong with dipped beam in fog, many cars I have owned over the years haven’t even had front fogs at all, even those that do have I very rarely switch them on, they make very little difference apart from keep a low flat beam of light designed to be below the level of water vapour (ie. Fog). The reason main beam doesn work is it’s a high beam that reflects back off the water vapour. The best foglights are square or rectangular not round as the reflectors keep the beam of light flatter.​

BTW. I’m an ex automotive electrical prototype systems engineer

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Rule 226​

You MUST use headlights when visibility is seriously reduced, generally when you cannot see for more than 100 metres (328 feet). You may also use front or rear fog lights but you MUST switch them off when visibility improves (see Rule 236).

Rule 236​

You MUST NOT use front or rear fog lights unless visibility is seriously reduced (see Rule 226) as they dazzle other road users and can obscure your brake lights. You MUST switch them off when visibility improves.

Edit….no idea why the text has gone bold above, can’t change it now & it wasn’t bold pre posting

 

[Gwgan]

Rules are rules, then there is the reality of instead of driving past my own rural driveway in thick fog I approach with just parking lights. Having low amber fog lights on without white low beams would be an improvement.

 

[haroldo]

Any chance we can stay on topic, every time we try to discuss HOW TO easily use the fog lights, it gets hijacked into a discussion on the various rules around the globe (#IDon'tCare), or whether people should, or shouldn't use them.

 

[Xdama]

Any chance we can stay on topic, every time we try to discuss HOW TO easily use the fog lights, it gets hijacked into a discussion on the various rules around the globe (#IDon'tCare), or whether people should, or shouldn't use them.

Ok, well they should be enabled when your headlights are on (low beam only). You then enter light control panel & push front or rear foglight button. They should go off if you put main beam on and turn off when your main lights are turned off. You should need to actively ie. Press the button anytime you want them on after the car has been switched off.

 

[BigNick]

Shouldn't true (front) FOG lights be yellow to amber in color?

The "fog" lights on my US M3P are actually auxiliary driving lights (white).

 

[Candleflame]

Shouldn't true (front) FOG lights be yellow to amber in color?

The "fog" lights on my US M3P are actually auxiliary driving lights (white).

front mounted lights in other countries are only allowed to be white (some may allow yellow too).
Amber is turn signals...

Strictly speaking what matters more than the colour is where they are mounted and where they shine to reduce fog glare.

 

[CanadaBill]

Tonight I went out to test the fog light settings we've been talking about. Turned on the Light Show, did a little dance around the new car and went back inside forgetting I went out to test the fogs. Gotta love these cars!!

 

[BillRadio]

Ok, well they should be enabled when your headlights are on (low beam only). You then enter light control panel & push front or rear foglight button.

I would like to make the case for our use of "fog" lights. Driving in heavy snow at night is brutal and I too think it is a misguided law to not allow fog lights-only. The advantage has less to do with light reflecting back to the driver and more with the ability to see the edge of the road, hence the broad beamwidth.

I have had people laugh at me for extolling the virtues of fog lights. They equate their use to fins on cars in the 50's. I have been in gawd-awful snow storms where I noted that my fog lights were worth a hundred times their cost keeping us moving and not falling over the side.

In previous cars I rewired the fog lights for just such occasions knowing law enforcement will not notice. I can't wait to go out to see if I can turn them on in the Parking Lights mode.

Also, don't confuse fog lights with "driving" lights which have a narrow beamwidth but are located in the same low position.

 

[Xdama]

I would like to make the case for our use of "fog" lights. Driving in heavy snow at night is brutal and I too think it is a misguided law to not allow fog lights-only. The advantage has less to do with light reflecting back to the driver and more with the ability to see the edge of the road, hence the broad beamwidth.

I have had people laugh at me for extolling the virtues of fog lights. They equate their use to fins on cars in the 50's. I have been in gawd-awful snow storms where I noted that my fog lights were worth a hundred times their cost keeping us moving and not falling over the side.

In previous cars I rewired the fog lights for just such occasions knowing law enforcement will not notice. I can't wait to go out to see if I can turn them on in the Parking Lights mode.

Also, don't confuse fog lights with "driving" lights which have a narrow beamwidth but are located in the same low position.

I don’t confuse them at all, I’m an ex vehicle electrical engineer. Foglights are for use in low visibilty (not just fog) their beam pattern is designed to be low, flat and wide. This enables them to reduce glare back from moisture in the air, be it water particles or snow. Absolutely noth8ng wrong with using them in a snowstorm as it’s reduced visibility, isn’t it