Hi.
It gets worse!!! I have an Aldi bulb kit I bought last year with H4 bulbs and others and just realised they are slightly tinted blue, I've just looked at them, not an E marking in sight except on the amber bulb. I've not used them as it was bought for bulb failure.
Very difficult for the unwary motorist.
It a BAY15D type in the DRL position as its a dual 21/5 watt filament.
Just thinking - wonder why no one makes halogen versions of these bulbs for a brighter light?
It's an utter myth that going to the blue end of the 'white' spectrum (which makes lights appear purple / blue at some angles) improves vision.
OEM bulbs (HIDs / LEDs) tend to run around 4300k - anything over 5000k looks blue-ish which will actually worsen your depth and contrast perception and make it difficult for oncoming drivers.
They also tend to cause blue / purple 'flashing' in mirrors.
Generally, those who fit these kind of bulbs will be idiots more concerned about how the car looks than safety - and will drive accordingly.
It may be a generalisation and stereotype - but I drive around 35k miles / year and most with bulbs from the blue end of the colour spectrum are awful drivers.
Because the heat would melt the lamps. The thing with "halogen" bulbs is that they run the filament at a much higher temperature. This causes tungsten atoms to leave the filament and condense on the colder glass causing it to blacken. The "glass" of "halogen bulbs is quartz and is run much hotter. The halogen part refers to the addition of a halogen to the gas fill in the bulb which promotes cycling of the metal back to the filament. The bulbs are sometimes called quartz iodide (quartz glass, iodine as the halogen). The whole lamp has to run much hotter so the halogen cycle can work. Unless the quartz is doped they also give out lots of UV light which can damage plastic lenses (I have a patent on using them for sterilising and drying microarrying pins using the UV and IR outputs).
Robert G8RPI.
Not all blue bulbs denote impaired driving skills or a need to be seen to be different - the W5Ws that come with a twin pack of Philips WhiteVision H4 bulbs are very blue...Wow! You can certainly gain some wonderful scientific insight on this forum.... sooo interesting. Thank you
Because the heat would melt the lamps. The thing with "halogen" bulbs is that they run the filament at a much higher temperature. This causes tungsten atoms to leave the filament and condense on the colder glass causing it to blacken. The "glass" of "halogen bulbs is quartz and is run much hotter. The halogen part refers to the addition of a halogen to the gas fill in the bulb which promotes cycling of the metal back to the filament. The bulbs are sometimes called quartz iodide (quartz glass, iodine as the halogen). The whole lamp has to run much hotter so the halogen cycle can work. Unless the quartz is doped they also give out lots of UV light which can damage plastic lenses (I have a patent on using them for sterilising and drying microarrying pins using the UV and IR outputs).
Robert G8RPI.