CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Replace headlights in pairs?

Do I really need to replace both headlights if only one has a burned-out bulb?

No. Just replace the burned out bulb. This even falls under the do-it-yourself category in most instances. A new bulb is just a few dollars at your local auto parts store.

Unless your car has HID headlights. They’re different, but they still don’t have to be replaced in pairs.

Right - please ignore the stupid bulb marketing ads (always replace in pairs). The only thing that helps is their profits.

If both are originals, I would replace one and carry a spare for when the other one burns out. Who told you that you had to replace them in pairs?

I would replace both and carry the one that was still working as a spare. Likely the second lamp is not far from going out anyway.

I would suggest the idea of replacing both is the likelihood that the second one is not far from going itself. Might as well do both now. Replacing one and not the other will not cause any problem with standard setups.

I would replace both and carry the one that was still working as a spare. Likely the second lamp is not far from going out anyway.

I don’t know about that…I’ve replaced one bulb on several vehicles and the other one finally blew 2 years later. My wifes 96 Accord I replaced one bulb at 4 years…We kept it for 10 years without the other bulb ever needing replacing.

You don’t have to, but it’s one of those things that you might what to do because you’re already at it. I’ve always done in pairs for uniformity. If you don’t have the same bulb as the one you’re replacing the light output and light temp can be different, and that just looks lazy.

Don’t replace bulbs that are still working. If one burns out the other could still last months or even years. Bulbs do not burn out in a predetermined time frame, and each bulb is 100% independent of the other.

Depends on you vehicle’s ease of replacement and the age of the bulbs. They’ve both seen the same hours of operation and the same road vibrations. If they’re as easy to change as my 92 Explorer then change just the one and carry a spare. If it takes tools and a half hour of dis-assembly/re-assembly then I’d do both while the tools are out and you already have the time invested.

Do modern headlight bulbs grow dimmer as they are used? If so, will the bulb that is replaced be brighter than the one that is still working?