The only true benefit of the Hg free version is environmental. They (D4S) are so marginally brighter than D2S that the difference is undetectable with the human eye. The push for Hg free is coming from Europe. They want to eliminate if from industrial use. The amount of mercury in a standard D2S bulb is extremely small. Best overal performance (cost, life, output etc.) is still D2S not D4S.

 

Here's the information I got on them.

D4S/D4R XenEco HID bulbs(part #42402) are a whole new generation of more environmentally safe and yet powerful HID bulbs. The bulbs are 100% mercury free and also have better illumination than their predecessors in terms of lumen level.

They also have a crispier, more bluish / white color (4800K vs. 4300K) without sacrificing the essential lighting power at all. You still get +600lm more / bulb than the traditional D2S even with the white color many of us search for.

The new generation Denso ballast was improved to apply increased initial operating wattage and operating current to the bulb, providing brighter lighting and longer bulb life than the conventional HID headlamp system. The ballast is approximately 50 percent smaller and 25 percent lighter over the conventional ballast. They used mostly in 2006 LEXUS vehicles.

 

We design State of the art HID ballasts and bulb systems for Aviation, Military (50 cal gun mounted) and industrial applications using this same technology. We make cylidrical, rectangular and conventional automotive shapes. Our smallest ballasts are as small or smaller than those being used for the D4S bulb. We also make 35 watt, 50 w and 75 watt ballasts.

The OEM automotive ballasts are all in the 35-38 watt output range including those for Hg free which operate at 42VAC output where the std D2S are 85VAC output. For the same wattage to the bulb the D4S require double the current.

I am very familiar with Denso, Philips, Hella and Osram ballasts. The newest Philips ballasts are made for them by Denso. Philips used to get ballasts made by Matsu****a mostly. The new Philips D4S and D3S arc tube mixture was developed as some kind of joint venture between Philips and Koito of Japan.

You are correct that the D4S and D3S are a little brighter and slightly bluer. The
D2S/D2R and D1S color shift up to about 4800K or so after 50-100 hours of use. The HG free bulbs and ballasts are more expensive at this time because the manufacturing volumes are much lower still than the standard stuff.

 

I was playing with the HIDs and it seems that perhaps the HIDs don't use a standard D2S bulb. It seems that we have bixenon Headlights with HID high beams too. Is this correct or am I looking at it incorrectly> Do we use a standard D2S bulb or a Duel Filiment D2S bulb? Additonal input would be very helpful!

 

Bi-Xenon is just a shutter built into the headlamp assembly. It has nothing to do with the bulb.

 

So does that mean there are two bulbs in there or is the voltage just changed when hi beams are turned on making it much brighter?

 

Just one bulb, no voltage change. What happens is that when the headlights are in low beam mode there is a little shutter blocking a portion of the beam. when you turn the hi-beams on the shutter moves releasing the entire beam.

 

sweet thanks for the input!