High Beam vs. Low Beam: What’s the Difference?

Understanding high beam vs. low beam lights and how they work is important for both safe driving and replacing your bulbs when they burn out. Depending on the make, model and year of your car, how these lights work and how many bulbs they take may differ. Here’s what you need to know about high beam vs. low beam lights.

What Do They Do?

High beams cast an intense light that can extend up to 400 feet directly in front of your car. This can blind oncoming traffic, so high beams should only be used in situations where they won’t affect other drivers. Low beams cast a light that extends about 200 feet, with a less extreme glare. Many cars have automatic high beams, but older cars require you to switch between your low beams and high beams manually. It’s always a good idea to make sure both sets of lights are working properly and to switch to your low beams manually as needed.

Are There Two Bulbs?

The answer to this question depends on your car. On most older vehicles, the answer is yes. It was once the norm to have separate bulbs for your high beams and low beams, but most modern cars have only a single bulb with two filaments on each side of the vehicle that performs the work of both the high beams and the low beams. There are a few different types of bulbs available.

HID and Halogen Bulbs

Many high-end and performance vehicles still have two bulbs. In these cases, a halogen bulb is used for the low beam, and a high-intensity discharge (HID) bulb is used for the high beam. These two bulbs are not interchangeable. If one burns out, you’ll have to replace it with a like bulb.

LED Bulbs

Many automakers use LED bulbs for parking lights, turn signals and various other headlight systems, such as fog lights, on their vehicles. These are some of the most energy-efficient bulbs available, as they draw far less energy from your car’s electrical system. Some manufacturers are using them for headlights as well, though this is less common.

Two Lights or Four?

One way to tell whether you have two lights or four is to look at the front of your car. If you see two headlight elements on each side, then you likely have separate high beam and low beam bulbs. If you only have one headlight element on each side, then you most likely have a dual filament bulb. If you’re uncertain, break out your owner’s manual for a definitive answer.

Check out all the light bulb products available on NAPA Online, or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information about high beam vs. low beam lights, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

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