Volvo S40: Rear Fog Lights?

The rear fog is show where the overtaking side of the car is in foggy weather. To simplify manufacture, Volvo (probably Hella) makes rear combi lamps with the option of having the rear fog function, and then at final assembly, the correct bulb is installed.

Some people install the other side bulb, either to look "cool" or some other reason. It's not proper and could confuse drivers when overtaking from the rear. Also, if both are on, it may confuse as to when the car is braking or not.

So, there should not be 2 rear fog lights, only the drivers side, whichever side of the road you drive on.

Jeff

What is confusing about having two rear fog lights? Do you just pass on the side that has a bright light? You shouldn't be passing in the fog. (The term overtaking is ambiguous, it can me coming up to and it can mean passing.)

One big advantage of two rear fog lights is that you can judge the distance of the car in front much sooner in fog, since you can see how far apart they are and judge the distance. Then you can stay back a safe distance. If you are going to rear-end someone in the fog because they have two rear fog lights, then you are following much too closely. Also, the brightness of the rear fog lights tends to keep people from tailgating.

A second big advantage of two rear fog lights is that if someone is tailgating in good weather, you can click on the rear fog lights every once in a while to make them back off. This is very effective and I do it all the time. Just as people subconsciously follow too closely, they subconsciously back off when they subconsciously think the brake lights are on. I hope you subconsciously understand this.

Says who?

In my view, two fog lamps are *far* safer than one. And all this stuff about confusion with brake lights is utter rubbish.

In the UK, many cars are supplied with 2 fog lamps, and some - particularly Volvo - with only one. Both options are legal.

Are you saying that those manufacturers which opt to supply two are improper in some way?

Of course, in some areas there isn't much point to having a car unless you are willing to drive in fog. I learned to drive in the California bay area, and fog was a fact of life. Pull over when you slow to a crawl, always be able to stop in the distance you can see, and there is no problem.

Mike

You're following a car with two rear fog lights on. You glance at the speedo, or into the mirror, or at the general situation on the road. Then you look back at the rear of the car in front. Now, has he put his brakes on in the meantime? Very difficult to tell. The danger is not so much if you wrongly conclude that he has put his brakes on, but if you wrongly conclude that he has not.

Personally, if I was in charge of the world, fog lights would be a different colour to brake lights. This seems so obvious, that I'm amazed that the rules in every(?) country require them to be the same.

Volvo and all other car manufacturers always mount the single rear fog light on the drivers side. That is primarily because the center of the road is most visible on curves. It has nothing to do with passing since people don't pass in fog do they.

Hi Stewart,

A nice distinction, but surely you would notice that the car in front now has FOUR bright red lights on, when previously there were only TWO................

Andy I. ( Isn't it interesting that this topic has generated one of the longest threads in this NG, again!)

| You're following a car with two rear fog lights on. You glance at the | speedo, or into the mirror, or at the general situation on the road. | Then you look back at the rear of the car in front. Now, has he put | his brakes on in the meantime? Very difficult to tell. The danger is | not so much if you wrongly conclude that he has put his brakes on, but | if you wrongly conclude that he has not.

| Stewart Hargrave | | | For email, replace 'SpamOnlyToHere' with my name

It sounds good, but in practice this is not always the case. Particularly in conditions of poor visibility, if the windscreen wipers are going, if the brakelights and fog lights are positioned close together, if there is a lot of other stuff to concentrate on too. Travelling at a safe distance you may not be able to distnguish the fog lights from the brake lights as distinct and separate lights. Visually ( to my eyes at least) putting two lights of the same intensity next to each other does not make me register a doubling of brightness, at least not in daylight.

A third brake light helps, but then you may not know that the car in front doesn't have one of these until it is too late.

Exactly. I don't know how it is in other countries but here in the Netherlands it is illegal to drive with the fog light(s) on when there is less than 50 metres of visibility.

In fog that thick, it is nice to have an orientation point to be able to keep your distance and even better, when the person ahead _does_ hit the brakes, you have plenty of time to stop.

Speaking of American cars... It amazes me that those cars are allowed to drive unmodified with the single colored one-lamp-fits-all design... One red light indicating the direction, brakes and regular lights... amazingly ineffective...

Arnoud

No the least bit difficult. All cars with rear fog lights also have a third brake light in the center.

Besides, with two rear fog lights, you can judge distance better and tell if you are too close. In fog, many cars slow down by just taking their foot off the throttle; the brakes are not used as much.

Actually FIVE, not FOUR.

Can we just stop this stupid religious argument? Use one light, use two lights, heck use 20 lights, I don't care personally, if the guy behind you is paying attention and has their eyes on the road it shouldn't be an issue in the first place.

Please, James, don't loose your religion over a rear fog light or two or three or four or five. You could just skip this thread you know. However you stated your opinion also, so you must be wrapped up in it.

You know that vehicles that leave their headlights on all the time have fewer accidents. That must mean that some people don't pay attention and don't have their eyes on the road. Unfortunately they need to be hit over the head with a 2x4 (bright lights in this case) to pay attention.