Halogen/HID FACTS!!

[mc84_zz4]

More like different levels of performance (and cost)

The H4 housings with H4 bulbs will give you a great improvement over stock headlights, and much better light control in fog/rain, since the H4 has a sharp cutoff line. The H4 bulbs can range from 1,200-2,400 lumens of light output.
http://www.rallylights.com/Hella_H4_Bulbs.aspx


The HIDs are truly an arc type bulb, using a ballast, and they will produce more light with less heat. The 4300 Kelvin degrees color bulb (true white) produce about 3,000 lumens, so the HIDs are brighter. The blue-er and 'ice'/cool-blue bulbs in this case are still bright unlike those cheap painted bulbs you see at Autozone, and each jump into a bluer range is about a 15% light filtering effect, but still brighter than stock.


Now there are HID retro-fit bulbs, a true HID bulb with an H4 base (also called re-based) that will fit the H4 housing, but many experience glare, and fly-away reflections, that are annoying to the driver, and to others a true hazard, as you temporarily blind incoming traffic. In this case you are fitting a bulb that is not designed for use in a reflector dish, as HID was designed for a projector lamp, with an integrated light cutoff plate. HID re-based bulbs have a clamped on metal filter for a cutoff for the low-beams.
Note the D2R (reflector HID) has a metal band around part of the 'capsule' (bulb) versus D2S (standard HID)
http://www.rallylights.com/detail.aspx?ID=306



If you have more-budget-than-shame, you can buy some very cool, true HID projector lamps made to fit older cars, these are DOT approved, but will set you back $500 a pair, or $1K the set of 4. These are the only DOT approved HID lamp for older cars that I know of.
http://www.spitzkraft.com/catalogue.php?catID=1



You can also tinker with adapting BMW HID projectors into the 4 1/2" round style, or cut an H4 reflector and adapt a projector HID from a BMW, Infinity into an H4 base, but that will take some time and skill to make, but the results can be worth it (unless you buy all the parts at retail).