All the exterior lights on your vehicle play an important role in your safety on the road. We like to say that lights “help you see and help you be seen”. Anything that makes your car or truck more conspicuous to other drivers assists them in determining your car’s position relative to theirs. While all exterior bulbs should be regularly checked for functionality, we suggest paying extra attention to the headlights, both low beam and high beam, as they are critical to the driver’s forward vision.
Starting in the mid-1980s, so-called combination headlamp assemblies, with separately replaceable bulbs inside their housings, became legal in the U.S. This style quickly replaced the round and rectangular sealed-beam lamps which had been in use since the 1940s. (You may find our article “A Brief History of Sealed Beam Headlamps in the U.S.” to be of some interest.) The good news is that a ‘headlight out” situation only requires replacing an individual bulb, not the entire housing. However, purchasing that bulb requires that you know exactly which bulb is needed.
This FAQ document is designed to assist those who are looking for a factory-style replacement bulb for their modern vehicles. While our website is designed to guide you toward the correct bulb for your vehicle, sometimes there are factory options you must know before making your final selection. In some cases, there are also bulb upgrades available in the same style bulb.
If you still have questions or need further assistance with your order, please do not hesitate to reach out to one of our trained sales associates who can assist you in making your final selection.
Q. How do I know my car’s bulb model name/number or “size”?
All replaceable headlight bulbs have a numerical or alphanumeric bulb “size” or “number”. Common examples are H1, H7, 9005, and 9006. Start at the www.carid.com website by entering your vehicle’s year, make, and model. Our site will show you the correct size bulb.
For example, for a 2010 Honda Accord sedan, the correct low beam bulb is a 9006, as shown by this ACDelco bulb here:
For a 2017 BMW 3-series sedan with factory halogen headlights, we find that the low beam bulb is an H7 as illustrated here by this Race Sport bulb:
Q. How can I determine if I have separate low and high beam bulbs, or a combination low/high bulb?
One way of making this determination is by examining the front of your vehicle while you or someone else alternates between the low beams and high beams. Vehicles which use a single combination low/high beam bulb will have light emanating from the same bulb. There may be a shield which moves to block off some light, or the bulb may have two filaments. Vehicles which use separate bulbs for low and high beams will clearly demonstrate light coming from two different locations within the headlight assembly.
When searching on CARiD, our site will prompt whether one is shopping for either the low beam or high beam bulb. Again we’ll use a 2010 Honda Accord as an example. For a Philips brand bulb, the drop-down menu allows you to select the low beam bulb, high beam bulb, or both:
Q. How can I determine if my vehicle uses halogen or HID/Xenon bulbs?
For factory-replacement bulbs (not aftermarket upgrades), it is critically important to know the types of headlight bulbs which were installed on your vehicle when new. Whether your car left the factory with halogen or Xenon bulbs, you must use the same type bulb as the replacement.
As an example, a 2018 Chrysler 300 could have left the factory with halogen bulbs or with HID/Xenon bulbs. You can see in the screenshot below that when searching on our site, we offer both, but as indicated, for the factory fitment only. The new car Monroney (window sticker) label will tell you, or your dealer should be able to tell you if you provide them with the VIN. Another option is to remove the bulb and compare it to the photos below.
Q. Are there options I can choose from for my replacement bulbs?
Some headlight bulb manufacturers offer a ‘good/better/best’ selection. For example, when shopping for a Sylvania headlight bulb for a 2014 Toyota Corolla, which takes a 9005/HB3 size bulb, one will find these choices in the drop-down menu:
Reading the text, we note that each upgrade produces an improvement in both brightness and spread. Of course, the bulb price increases, but not drastically.
Philips is another example of a brand offering different performance levels for their halogen bulbs. As you can see below, in this case, the manufacturer offers 4 choices, so the shopper is certain to find a bulb that meets their needs at their desired price point.
Q. Once I know my bulb’s size, is there an easier way for me to order replacements?
For those who know the bulb’s size, we have a special department on our site called Shop By Bulb Type.
As an example, using the Refine Search menu on the left, keying in “9005” under ‘Bulb Socket’ gives us this result:
From this point, one can choose the brand and price point of their desire. By the way, this bulb type functionality works for all other car bulbs too, not just headlight bulbs.
Q. Many headlight bulbs are sold in pairs, so should I replace bulbs in pairs?
Bulbs are sold in pairs for convenience; one reason is that, should you need another, you’ll have it on hand. Many drivers like to keep a spare bulb in the glove box because driving with only one operational headlight is both dangerous and likely to cause a summons. However, there is another reason for selling bulbs in pairs. Modern halogen and Xenon headlight bulbs tend to get dimmer over time, almost unnoticeably so. For that reason, we suggest the best practice of replacing headlight bulbs in pairs, ensuring that you always have the maximum amount of light in front of you.
Be sure to check out our other headlight-related articles:
Shopping Guide - Custom & Factory Headlights
Care And Feeding Of Your Composite Headlamps
Factors To Consider When Purchasing A Replacement Factory Headlamp
LED Headlight Conversion Bulbs - The Cost-Effective Way to Better Lighting