When to change headlight bulbs

Scot22

Interested in what people do and what they spend.
Do you wait until one fails or have a time to replace.

AdrianC

Wait until failure.

There's no way to predict their life - they may last months, they may last many years.

I don't believe there's any benefit whatsoever in the over-hyped, over-marketed, coated bulbs. All coatings do is filter out part of the full spectrum of light emitted.

DiddyDavies

If you change a headlight bulb before it actually fails, where would you draw the line?
Brake light bulbs, indicator bulbs, sidelights etc?
It would start getting very expensive changing all the bulbs on a car for no good reason and you could end up spending money on a new bulb only for that replacement to fail shortly after fitting it.

oldagetraveller1

When one fails. I would change as a pair because if the other is the same age, sure as night follows day, that will fail soon too!

Mine are H4 halogens, original Osram, and will be replaced with the same when the time comes.

AdrianC

oldagetraveller1 said:

When one fails. I would change as a pair because if the other is the same age, sure as night follows day, that will fail soon too!

Nope, doesn't work like that. I've had one go and the "pair" has lasted for years.

Car_54

oldagetraveller1 said:

When one fails. I would change as a pair because if the other is the same age, sure as night follows day, that will fail soon too!

That hasn't happened in my experience (which goes back to 6 volt systems!). Except perhaps on my Rover 820, where everything electrical failed at least once.

Scrapit

Only change when failed. Its not very MSE to replace a perfectly good bulb. What do you do in the home?

Scot22

Appreciate posts.  Support my wife's view so I'll forget it 😊

photome

oldagetraveller1 said:

When one fails. I would change as a pair because if the other is the same age, sure as night follows day, that will fail soon too!

Mine are H4 halogens, original Osram, and will be replaced with the same when the time comes.

Not my experience, I have often changed just the one without ever changing the other one


if you have 2 lamps in one room of your house would you change them both if one went

pogofish

With the more modern halogen/capsule-type lamps, I also find that when one fails, the other probably won’t be that far behind it - maybe by a matter of a couple of months, but their higher running temp does mean that they have a more finite lifespan so once one goes, I ensure I have a replacement of the same type in the boot for when the other goes.

With older/less pressured filament lamps, yes it’s a different matter as they can last a lot longer and there is no reasonably immediate need to keep a spare on hand, although I do try to keep a few spares for the essential lamps in the boot at all times.

Another point to consider is that lamp changing on modern cars can be such a pain in the behind that it is often easier to just get it over with and do them both in one-go, esp for some vehicles that are so difficult that a garage is often needed and they often charge a fixed price that is not that much appreciably dearer to do both at once.

And yes, I am that annoying guy who insists on testing out bulb replacement in the showroom. Having been caught-out once, I now simply will not consider buying a car where I can’t replace the main/legally required lamps myself!

pogofish

photome said:

if you have 2 lamps in one room of your house would you change them both if one went

I have just done exactly that - one failed and when I put-in a replacement of the same make and wattage, it was immediately apparent just how much the quality of light had faded/deteriorated in both lamps since they were last replaced maybe three years ago!