headlight vs fog light

Headlight vs Fog Light: What’s the difference?

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Having to replace lights on a car can be a headache. Trying to determine what type of lights you need and the specifications that will work with your vehicle can be downright frustrating. If you’re new to cars, you may not know the difference between headlight vs fog light. Luckily, we’ve got you covered! If you’re looking to replace a light on the rear of your vehicle, check out our article on brake light vs tail light.

What are Headlights?

A headlamp or headlights of a car is a pair of lighting devices (bulbs, LED, and others) that are installed on the front end of the vehicle. Its purpose is to illuminate the road ahead at night for safer and easier driving. The headlight is primarily a car accessory that promotes and maintains safety on the road.

Universally speaking, all cars must have headlights to become legally registered. Any vehicle without headlights is deemed illegal and will not be allowed to traverse public roads. The way the headlights are installed is done to maximize safety and convenience when traveling at night. Its photometric value, design, types of bulbs, and color are all standard and regulated by law.

How does It Work?

Most people would interchange the term headlamps with headlights. But if you were to break it down technically, headlamps are the actual bulbs or LEDs at the front of your car, and headlights refer to the total area of the road covered by your headlamp beams when it is turned on at night.


Dipped Beam or Low beam

Most of the time, a dipped, or low beam is the headlight setting used by drivers when traveling at night. This applies to all kinds of places, whether you are within city limits or in suburbia. On a stock headlight, the dipped beam mode is set up at an optimal angle to cover as much road as possible in front of the car, while it gives the driver maximum view ahead without dazzling the drivers of approaching vehicles. One must stay at dipped beam mode unless it is necessary to go high as specified by law.

High Beam

This mode is the brightest among all settings as it illuminates everything in front of the car and all of the road far ahead. This setting is mainly used in stretches of unlit roads. High beam is so powerful that it can overwhelm oncoming drivers, pedestrians, and other motorists to almost being blinded by the light. This could become the cause of unwanted accidents, which is why the use of high beam is limited by law.

Indicator Lights and Hazard Lights

Left and right turn indicator lights are located at the front and the back of the vehicle. They serve to flash and alert pedestrians and other motorists to indicate the direction of your car turning left or right.

Headlights and the Law

Aside from exercising prudence when using high beam, it is important to know the basics of its limits. The legal use of high beams differs from state to state in the U.S., although some have similar rules that apply to many other states. For example:

  • Most states allow the use of high beams when the driver can’t see anything within 500 feet ahead of him or her. And the driver must switch to low beam when there is oncoming traffic within 500 feet.
  • Headlights must be on when visibility conditions are poor, may it be day or night.

These are just a few of the laws in the United States governing the use of headlights and high beams in particular.

What are Fog Lights?

Fog lamps or fog lights are headlights that can be round or square-shaped and are located on the bumper, right under your car’s regular headlights. Most cars in the past would have yellow fog lights that penetrate fog well without the glare, as it is easier on the eyes too. Any driver with good common sense will turn on their fog lights (if the car is equipped with one) while driving in poor visibility conditions.

Not doing so is simply running blind and is dangerous.

How Does It Work?

Below are some examples of road conditions where the driver’s vision is severely limited:

  • Rainstorms
  • Thick fog
  • Smoke and or dust
  • Snowfall
  • Low cloud
  • Any other road condition that severely limits the driver’s vision

Fog lights are not too bright but are penetrating powerful lights that are sharply angled downwards. They are angled much lower than your headlights. Remarkably fog lights don’t touch the ground but are angled as close to the road as possible. The purpose of this is to penetrate fog or heavy rain with light and illuminate the ground just ahead of you while you move along without blinding oncoming motorists.

For fog lights to do its job without reflecting too much light coming in back from the fog, it must be positioned to project a flat horizontal beam that produces better brightness and visibility than your regular headlights. On the flip side, however, if you turn your fog lamps on ordinary nights, oncoming traffic may be blinded by the extreme brightness of these lights, and it can be dangerous enough to cause accidents.

Technically, fog lights are much safer in low visibility situations only because regular headlights reflect more light from the fog into the eyes of the driver as compared to fog lights.

Rear Fog Lights

Rear fog lights are the same lights from the front of your car added on to your rear bumper. It functions in such a way that it benefits you and the driver behind you. Rear fog lights are designed to help the driver that is following you to correctly estimate the distance he needs to put between you and him during low visibility conditions.

Running behind cars with rear fog lights makes driving for drivers under low visibility much easier. It might seem like a small detail but is such a big difference in safety and accuracy. There aren’t many vehicles in the U.S. that have rear fog lights, as it is not required by the National Highway Traffic Safety Administration. If you want rear fog lights, you may go to an aftermarket dealer and have them help you install it too.

Fog Lights and the Law

Fog lights in the U.S. are considered optional accessories to motor vehicles and are therefore not required. They have dimmer output and are meant to help by creating an extra beam of light along with the main headlights in negotiating low-visibility situations. However, as a general rule, fog lights should be used only when visibility drops lower than 100 meters or 328 feet.

Since fog lights are just supplementary, we recommend using them only when necessary and at low speeds in foggy situations. It is illegal in most states to use fog lights when visibility is okay. The driver may incur fines and a potential suspension of their license. Be reminded that light rain is not considered poor visibility; hence, it is still illegal to use fog lights when in a drizzle.

You can use your high beam instead, as you can do this while still following the 500 feet rule. Do not forget to go low beam when there is oncoming traffic. More importantly, it is illegal to have only your fog lights on in most states. This is regardless of any weather conditions. Fog lights are short as they only illuminate some distance in front of your car, making it unsafe.

What are the Key Differences Between Headlight vs Fog Light?

· Generally, headlights are square, and fog lights are round. Each has its unique design and assembly.

·Headlights are installed stock in the front and center of the car, while fog lights are always located below the headlights on the bumper.

·Headlights project farther upfront in the direction of the middle of your vision. Conversely, fog lights have shorter beams and are angled downwards to cover an area that is intended to be smaller but penetrating, which also prevents glare from the fog.

·As required by law, headlights come standard in every vehicle that carmakers produce. In contrast, fog lights often come as an optional upgrade for cars, or an optional aftermarket install.

·Headlights are the primary lighting accessory for normal driving conditions at night. It is always turned on any time the vehicle is in motion, as it would be illegal and dangerous to run around with your headlights off at nighttime. On the other hand, fog lights have a separate switch to be turned on only when visibility is poor or when there is fog, heavy rains, snow, and other unusual weather conditions.

·Standard color of headlights is either white or light yellow. In comparison, fog lights are, at best, generally preferred by drivers to be yellow, making it is easier on the eyes and is also better at penetrating fog. Although nowadays, bright white fog lights are increasingly becoming commonplace.

·The use of headlights in the U.S. is regulated in a way that you will have to turn them on 30 minutes before sunset and turn them off 30 minutes before the sun rises. Conversely, fog lights don’t have a specific law to follow except that they should only be used whenever necessary.

Final Thoughts

Since we already know the difference between headlights and fog lights, we now know when and where we can use them either separately or together when driving at night in any possible weather condition.

If you spend most of your time on the road, whether for work or business, having fog lights is no longer an option but already is a requirement. Just like a hand torch, a pair of good reliable fog lights will always help you get through a foggy or snowy night, where it’s just you, your car, and that big stretch of road in the middle of nowhere.