blown light bulb - what to replace?

[Noodles]

I get it, thank you for the explanation. I can be a bit daft at times. (my wife says all the time)

I am probably going to jinx myself but we are going into year nine of getting the Osram replacements from a third party and at about 40% less than MB dealer pricing. I recall when I installed them that the Osram numbers were identical to the OEM bulb that came out.
Not sure why the OEM bulb failed, but I replaced the pair and kept the working OEM MB bulb in a plastic capsule near in the jack storage compartment. That way the truck always has a spare just in case one decides to fizzle out.

For some owners the dealers mark up parts over retail and for others the dealer is so far away that the fuel and time is not worth it. They have two choices at that point. One would be to get them online from a third party. Second would be to get the Silverstar bulbs because it is just convenient and makes more fiscal sense because the did not spend $30 on fuel going to the dealer.

[sparky1016]

[QUOTE=Noodles;5576432] but I replaced the pair and kept the working OEM MB bulb in a plastic capsule near in the jack storage compartment. That way the truck always has a spare just in case one decides to fizzle out.
QUOTE]

This is exactly what I did. As soon as I found out I had a blown bulb, I replaced it with my spare I was carrying in the console. My new replacement Silverstar Ultras on their way, I'm good to go until then.

I'm not worried to have the bulbs replaced every 5 years, but I'm more worried about not having bright headlight at night when I have to drive some place I'm not familiar with or unknown terrain.

[DrX]

Originally Posted by sparky1016

I read in a lot of places, the OEM bulbs are not very bright(intentionally) to begin with and then will lose 20% or more of light output after 5 years or so.

One of these bulbs is 10 years old, the other is 2 years old.

I wouldn't say there's a 20% difference.

[Wragie]

The sylvanias you have coming are good ones I just put them in mine about a month back. Replace in pairs don't just do one. As they age the resistance changes and you can get an uneven load on the system. The 20% fade in output happens in the first year or two. You won't see much difference but it will mainly be in the fill and edges of the lighted area. If you can see a difference in the output like in Drx's bulbs then its time to replace. If you look at his picture you can see a difference in the details of the bulb and reflectors etc. Visible light differences indicate much more than 20%.

FYI bulbs manufacturer's will actually tell you to replace the bulbs yearly especially if the bulbs are lit all the time ie daytime running lights.

[sparky1016]

The ligth output of your right/left look a little bit different - left side looks a little dimmer than right. But I can only think it may be, you should know much better with your own eyes.

If you feel you have sufficient illumination, then it's great.

BTW, 20% loss of light output after a few years is not a guess, rather a scientific measurement, was told.

Originally Posted by DrX

One of these bulbs is 10 years old, the other is 2 years old.

I wouldn't say there's a 20% difference.