AC vs. DC HID bulbs

[Mounce]

Does anyone know if there's a difference between AC and DC bulbs? I know there's a difference between AC and DC ballasts, but what about bulbs? I've done a ton of google searching and haven't found any info. I have seen, though, that there's not a difference between 35w and 55w bulbs, anyone know if that's true?

 

[BlazingTrails]

Hahaha!!!

 

[Mounce]

What?

 

[dmanns67]

From what I have read, you are looking at around 3200 lumens produced by a 35w 4300k HID bulb. At 55w you are looking around 3800 lumens from a 4300k HID bulb.

Also, the lifespan of a 55w HID bulb is drastically less (1,000-1,500 hours) than a 35w HID bulb (3,500-5,000 hours) due to useage which erodes the bulbs electrodes over time. This causes the arc inside of the bulb to get longer which takes more voltage to maintain the arc. Once your ballast reaches its max voltage output, the 55w HID bulbs will fail.

From everything I have read, 35w HID bulb is the way to go. Not only do they last longer, but I have seen pics of inside of projectors where the heat from a 55w HID bulb has damaged the reflector bowl inside of the projector which makes it useless. Not to mention having to replace your 55w HIDs more frequently.

 

[Sparky]

AC wins every time for HID. Some sellers try to make DC sound better, but that's because they profit from them as they are real cheap to make. By the way, the ballast is what determines the AC vs DC. Bulbs are the same (though the same bulb will last longer with AC over DC).

Also, if you're using projectors - which you should be for HID - then use whatever bulb fits best. Some can't use more than 35W because as mentioned above the 50W will damage the reflector bowl. Some larger projectors are designed for 50W.

If you're being cheap and using your stock headlights, then absolutely do not use 50W HID in those. Keep in mind that a 35W HID bulb has near the same lumen output as a typical halogen high beam bulb. a 50W HID is far brighter. Other traffic would really hate you if you used 50W in your stock lights.

 

[Mounce]

Thank you both, I guess what I was getting at was whether or not I could put 55w ballasts on the bulbs I currently have (35w) or would I have to get new bulbs too. And yeah, I know the deal about the factory lights and blinding people. I had my 35w HIDs in factory headlights for a couple months then got some aftermarket headlights, still not projectors though. I adjusted/aimed both sets after installing the HIDs and haven't been flashed by oncoming drivers once. Btw, this isn't referring to my GMT, this is all regarding my Mustang.

 

[dmanns67]

You can run a 55w bulb on a 35w ballast, but I would not run a 35w bulb on a 55w ballast that is designed for 35w. Supplying excessive voltage might cause the bulb not to fire or fail prematurely.

 

[Mounce]

Thanks, David.