Hey! You! Turn Your Damn Fog Lights Off!

In Christianity, there are only seven deadly sins you can commit: wrath, lust, greed, sloth, gluttony, envy and pride. In the Sacred Religion of Motoring however, the list of capital vices you can succumb to while behind the wheel is seemingly endless: chatting on a cell phone and going any amount under or over the posted speed limit are among the many evils.

One evil on the list brightly stands out among the others however, almost blindingly. And like drunk driving, tailgating or failing to yield before lethargically puttering onto a double-nickel highway, this particular sin could very well send you to the icy bowels of the Ninth Circle to play poker with a grieving Lucifer — driving with your fog lights on when fog is suspiciously absent.


Here's a situation that I know we've all encountered: It's late at night and you've finally made it through yet another gruesome day at work. And because your day was terrible, you have a slow dull headache lazily making dinner out of your temples. You're stressed, tired and want to go back to your quiet home located conveniently away from the noise and hatefulness in the cold heart of the Big City.

Driving conditions are excellent and traffic is very light on the way home. You unwind a bit now, your headache starts to fade. That's when you notice a blip of light swiftly approaching you in your rear view mirror.

You shrug it off at first, but before you know it some heathen sociopath in a massive SUV is breathing down your neck, the front of his grotesque four-wheel drive covered wagon lit up like a Colorado Christmas tree; both his headlights and fog lights are on. The glare is horrific and induces your headache to return, and it's decided your cranium is an all-you-can-eat buffet. Until you reach your driveway, you have to tolerate this peon who seems to insist that, despite obvious evidence to the contrary, visibility is so poor he needs to be recognized as a celestial body by NASA.

Now this where I would continue to rant and ramble about how much fog lights irritate me and so on before I plea and beg for other drivers to repent and keep them off unless the proper circumstances present themselves. But that's not going to do the job alone. Nope, this time I'm bringing a small number of burly-chested facts along to crash the party.


Fact One: "Fog Light" IS NOT a Synonym For "Driving Light"


In the example above, the sadist behind the wheel of his truck-based whale shark seems to think that his fog lights also double as driving lights. Well, let me be the first person to say that's wrong, wrong, wrong.

So what exactly is a fog light? Or a driving light? How are they different? Grab a cup of coffee, a good beer or whatever else you need to get you through this possibly pedantic and very factual lesson. It isn't exactly curt and dry (rev up your keyboard, Old Biff, I said that just for you).


According to something called the dictionary, a fog light is "an automobile headlight throwing light of a color intended to diminish the effect of fog, dust, etc., in the air." Fair enough, but I'll be completely honest, the dictionary's definition leaves something to be desired.

For starters, OEM fog lights rarely throw "light of a specific color" these days. While at one time they used to cast what's known as "selective yellow" light — mainly because the French thought ugly yellow light reduced glare — most modern fog lights cast white light instead. The reason for the change is partially cosmetic, but it's also because the amount of glare selective yellow light reduces is actually negligible.


Fog lights are also intended to be mounted low on a vehicle (at least in the front bumper) and the beams they project must have a sharp cutoff at the top so that they illuminate below a vehicle's low beams and light the road immediately in front of you. This is, theoretically, what makes a fog light useful in poor weather conditions such as, well, fog as well as snow or heavy rain: the low mounting position and specific illumination.

A driving light on the other hand is, according to Wikipedia, an auxiliary high-beam light "fitted to provide high intensity light to enable the driver to see at longer range than the vehicle's high beam headlamps."


I like Wikipedia's definition here for the most part except for one thing: it doesn't mention where a set of driving lights should be positioned. In comparison to a set of fog lights, driving lights are mounted higher up on a vehicle, typically just above the bumper and ideally below the headlights.

Confused? Luckily, the two Jeep Patriots above will gladly illustrate the visual difference between the two.


Short answer: No, fog lights are not driving lights, nor are they substitutes for them. Don't use them unless you're driving over the Golden Gate Bridge at six in the morning, or if you suddenly find yourself in the middle of a snowstorm in Minnesota. Don't turn them on if you can see the cheese on the moon's surface or if it's in the middle of the day.

Fact Two: The NHTSA Does Not Regulate Fog Lights, Never Has


Here's some food for thought: Headlights, taillights, and center hi-mounted stop lights (CHMSLs, aka third brake lights) have to conform to NHTSA safety regulations and DOT federal regulations. Unlike other automotive lighting systems, fog lights are not regulated by either institution and only have to meet SAE standards which, according to a recent NHSTA study, are "outdated." After all, the SAE's root criteria does date back to sometime during the Great Depression.

Say what you want about the NHTSA and DOT, if fog lights were federally regulated, there would be stringent modern standards as to how a fog light would function. I'll also hedge a bet here and say that, if either the NHTSA or DOT started regulating them, many designs on the market wouldn't be up to snuff. But, because the fed is strangely absent here, that brings me to our next fact ...


Fact Three: They're Not As Useful As You'd Think


So, how effective are fog lights anyway? Before we answer that question, let's recap what we've learned so far.

1. Fog lights must meet the following criteria:

  • Project a beam of light with a sharp cut-off at the top so that they illuminate "below" a vehicle's low-beam headlights.
  • Be mounted low on the vehicle, typically in the front bumper if not somewhere lower.

2. The DOT and NHTSA do not regulate the performance, functionality nor safety of front fog lights.

With that in mind, few fog lights are likely useful in poor weather conditions because: a.) automakers often tend to take liberties with how they design them and where they position them (after all, Uncle Sam isn't telling them what to do); and b.) the very nature of some vehicles prohibit them from being useful in the first place.


With regards to point a, let's use the outgoing Ford Mustang GT as an example since its the one I find the most irritating. When you spec your Mustang with the GT package that includes the 5.0 Coyote V8 and some big wheels, Ford throws in a pair of fog lights as part of the deal. Usually considered by Ford fans to be a nice retro touch, the Mustang GT's fog lights are placed in the grille immediately next to the front headlights like the original from 1964½.

Now reference the criteria above. See the problem already? Sure they look cool, but after your done welling up over your grandpappy's old Mustang you'll quickly realize that Ford didn't throw in a set of fog lights as part of the deal. And before you say it the answer is no: they're not driving lights either, they're really mounted too high up. So what Ford has really done is given you something as pointless as breast implants on George Clooney.


It's also that same criteria that explains point b. Because the DNA of vehicles such as pickups and SUVs makes them tall, one equipped with fog lights is only good for causing headaches. And unless you want to mount them on the bottom of the oil pan, they really aren't all that great in poor driving conditions either.

Porsche 918s Don't Have Fog Lights: Other Miscellaneous Facts and Observations


The party isn't officially over until someone urinates in the punch bowl. And I'm afraid that time has come. So I'm going to wrap this up with the following shower of golden information.

  • In 2012, British insurance firm Swiftcover reported that 300,000 accidents in 2011 were caused by someone improperly using their fog lights. This is in a country where drivers can be fined for doing so, so I can only imagine what that same study would look like here in the States where we don't.
  • Some drivers say that they like to flip on the fog lights on their Nissan Versas and Honda Civics because they think it looks cool. Okay, whatever. You want to know what looks cooler than a Nissan Versa with its fog lights on? A Porsche 918. And a Porsche 918 doesn't offer fog lights even as an option at any price. Neither does any other supercar or hypercar on the market that I can think of.
  • For a second, imagine a world where fog lights aren't optional equipment. It's a pipe dream, sure, but if the demand for fog lights suddenly fell off of the face of the Earth tomorrow, that would spell the end of big gaping flesh wounds on the face of every entry level car built.

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