Dimmed high beam as DRL?

[Ot_tO]

Hi :smile: ,

in some countries the high beam is dimmed that it work as daytime running light.

Just curious, how much?

For example, my Yaris (signature :wink:) have a H4 bulb in the headlight.
So this mean, 55 W for low beam and 60 W as high beam.

E.g. Hella make a DRL lamp with high beam or fog lamp combination.
This lamp have a H15 bulb, 15 W as DRL and 55 W as high beam or fog lamp.

If I would buy the Yaris in a country which have DRL with dimmed high beam, how much dimmed would be the 60 W of the H4 bulb? To 15 W - 25 % of the 60 W?

Thanks. :smile:

[CTScott]

The DRL module pulses the high beam bulb with approximately a 50% duty cycle. So, it gets full power, but for 50% of the time, so theoretically it looks about half as bright.

[Ot_tO]

You mean with *pulse width modulation* (PWM)?

Which countries have this dimmed high beam as DRL?

(Which countries have dimmed low beam as DRL? At which %?)

I read, the bulb should run at least with 76 % of max brightness.
If not, it will reduce the life of the bulb, because it need certain amount of heat for the regeneration.
This could be correct?

How are the experiences of the owner of such cars with dimmed low/high beam as DRL?
You need every few months new bulbs?

Thanks. :smile:

[CTScott]

You mean with *pulse width modulation* (PWM)?

Which countries have this dimmed high beam as DRL?

(Which countries have dimmed low beam as DRL? At which %?)

I read, the bulb should run at least with 76 % of max brightness.
If not, it will reduce the life of the bulb, because it need certain amount of heat for the regeneration.
This could be correct?

How are the experiences of the owner of such cars with dimmed low/high beam as DRL?
You need every few months new bulbs?

Thanks. :smile:


Yes it is PWM. The US and Canada have the DRLs with the high beam filament being PWMed. I am not sure of the exact percentage, but the one time that I connected a little hand-held oscilloscope to it to see how it was being driven it looked to be about 50%.

With the OEM bulbs this does not seem to affect their life span. I run aftermarket bulbs (Sylvania Ultrastars) and they typically last about 18 months, but only the low beam fails at that point. The high beam filament is still good when I replace them.

[Yaristeve]

How are the experiences of the owner of such cars with dimmed low/high beam as DRL?
You need every few months new bulbs?

My 2004 IS300 has dimmed high beam DRLs. Don't know what technology or how they do it. It still has the original bulbs. But the car only has about 28,000 miles on it.

[Qmobile]

If you ask me....honestly the DRLs on my '08 seem like just slightly dimmed low headlights. I see very little difference in the DRL and Lows