So to answer your questions. Yes the OEM halogen headlights are different from the OEM HID headlights. What are the differences you ask? Both use a reflector and focus the light through a lens (this is commonly called a projector housing). The HID light has a slightly clearer lens for better clarity, and the shield on the reflector (thing that gives the precise cutoff) is separate and can be adjusted. The HID lights also have the manual leveling motor so that you can adjust the lights when you load a bunch of weight into your car and not blind people.

Any H7 HID kit will fit into your OEM halogen headlights. The difference between one of these kits and HID-like bulbs is that those are still halogen and use a filament, whereas the HIDs arc the current between two electrodes through xenon gas. It's the same concept as flourescent lights. HIDs will provide 3x the light output as halogen lights. The DS2 lights are what are used in the OEM HIDs. These bulbs won't fit into your headlights (they're longer), so as I said you'll need a H7 HID bulb when you order.

I would suggest you stay away from an ebay kit. You may save money, but what happens when something craps out and you don't have a good warranty. Most online forums have sponsors selling HID kits that will give you a lifetime warranty. Piece of mind is a great thing.

If you go with one of those kits you won't end up with the precise "razor-thin" cutoff that you see on OEM HID lights. If you really want to get a good cutoff the you'd need to replace the projectors in your lights with better HID specific ones. As someone mentioned Acura and Honda projectors are favorites for retrofits.

 

its really not that serious were you would want to change/ retrofit another veicles projector housing to your car so you can have "true HID cut off" the whole point is to get more light and with a conversion kit you will achieve that and contrary to what some may think projectors be it halogen or HID will always to a great job at controlling the light from scatter. Every customers car that i have ive install an aftermarket kit in with projectors are very happy with the results and ive only come across one incident where there was a problem, only reason for that was beacue the custer did not want to wait for the proper kit to come in and decided to do the silicon and glue install.. I have a kit in my car (a6) that had halogen projectors and the cut off is great i will take pictures if anyone wants to see. ive also done an install in a mazda 3 and achieved simular results.

You are correct though a housing that was made for HID is alwasys the best But you can achieve very comparable results without hacking and cutting your car up to retrofit someother vehicles lights. You might also want to note that some staes will fail you for inspection if you aftermarket HIDs no matter what kelvin. You can always go back to stock with the correct kit for whatever reasons.

 

I'm not saying that HID kits in halogen projector housings don't work, I'm saying that they don't look as good as true HID projectors. The frosted lens and imobile shield make the cutoff less precise. Also you don't get as much color on the edges of the cutoff, and lots of people are looking specifically for that. I do think that it's a bad idea to put HIDs in reflector housings though.

btw aftermarket HIDs are illegal in the entire US, not just some states, for on road use. If you're concerned about being failed during inspection then just spend a little extra time making sure your ballasts and ignitors are hidden from plain view. Most inspectors seeing the 3 probably will just think the HIDs are OEM unless they see big ballasts attached to the top of the engine.

 

yes they are illegal for on road use in the US thats true but like you said. most inspectors wont know unless its obvious but if you do end up with an inspector that notices, it would be nice to be able to go back to stock within minutes. and if you sliced and diced yuour car to get another cars HID projectors in then that would be a little too difficult.

 

I'm not saying don't do it because it's illegal, just pointing out that it was in fact illegal. Just in case there were any allusions to the contrary.