# H1/H3/H7 light output difference?



## silver_arrow_jetta (Jul 30, 2004)

does anyone know if there is any light output diferrence between this buls types considenring all being in projector and not in reflective headlights. thanks


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## Cullen (Apr 5, 1999)

*Re: H1/H3/H7 light output difference? (ravipedrosa)*


_Quote, originally posted by *ravipedrosa* »_does anyone know if there is any light output diferrence between this buls types considenring all being in projector and not in reflective headlights. thanks

H7 is a newer version of H1, H3 has the filament the other way hence used in different applications like mainly spot high beams and foglights
As for OUTPUT there is not a difference between the bulbs per say


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## silver_arrow_jetta (Jul 30, 2004)

*Re: H1/H3/H7 light output difference? (Cullen)*

with that said i can easily replace an h7 for an h3 without losing anything lightingwise?


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## Cullen (Apr 5, 1999)

*Re: H1/H3/H7 light output difference? (ravipedrosa)*


_Quote, originally posted by *ravipedrosa* »_with that said i can easily replace an h7 for an h3 without losing anything lightingwise?

Same housing!? you cant swap bulb types like that in the same housing (and why would you?)


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## silver_arrow_jetta (Jul 30, 2004)

*Re: H1/H3/H7 light output difference? (Cullen)*

im replacing the housing as well (retrofit project)


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## dennisgli (May 17, 2003)

*Re: H1/H3/H7 light output difference? (ravipedrosa)*

From Daniel Stern Lighting:

_Quote »_
BULB TYPE ... WATTAGE .... LUMENS
H1 ............... 55 ............... 1550
H3 ............... 55 ............... 1450
H7 ............... 55 ............... 1500
H9 ............... 65 ............... 2100


H9 is the only one that puts out significantly more light - but I've never seen an application of an H9. If you want more light I'd upgrade wiring, add a relay, and use a high wattage H7.


_Modified by dennisgli at 7:33 AM 2-5-2005_


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## vr6ofpain (Feb 5, 2004)

*Re: H1/H3/H7 light output difference? (ravipedrosa)*


_Quote, originally posted by *ravipedrosa* »_with that said i can easily replace an h7 for an h3 without losing anything lightingwise?

NO
An H3 has horizontal filiments, the H7 and H1 have axial filiments. The light output would be probably be negatively affected.


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## Cullen (Apr 5, 1999)

*Re: H1/H3/H7 light output difference? (ravipedrosa)*


_Quote, originally posted by *ravipedrosa* »_im replacing the housing as well (retrofit project)

from WHAT to WHAT?


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## silver_arrow_jetta (Jul 30, 2004)

anyone else?


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## Bugging55 (Oct 2, 2002)

*Re: (ravipedrosa)*


_Quote, originally posted by *ravipedrosa* »_anyone else?

If you are going to use an H3 bulb and you say you want to "retrofit", then you need to retrofit a projector (assuming thats what you are using) that is designed for an H3. Same goes for any other type of bulb. You need to use each type of bulb with the housings they were designed to be used with.
There is a lot more to the bulb/housing relationship than just the orientation of the filament (which is one of the biggest concerns). You also have to ensure that the filament is positioned in the right location. You need to know that it isnt too far forward, or backward or too low or too high.
For instance the filament on the H7 bulb is offset lower by 0.5 mm from the axis of the bulb. Its centre is something like 25mm from the base of the bulb. So, all of these things need to be taken into consideration. What this basically tells you is that putting any OTHER bulb into a housing that was designed for a particular bulb is not a good idea.


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