<<The HID's take a few seconds to come up to full brightness. Mercedes accommodates this delay by using them for the low beams and using > standard xenon's for the high beams and the HID's stay on when you switch to high beams>>
The earlier low-beam-only Xenons use an 55W H-7 bulb for high beam with a separate reflector and lens. MY '01 C320 came with the low-only xenons which I converted to Bi-Xenon (complete replacement of the light units and huge improvement $$$) and the H-7 high beam is retained, presumably for high beam flashing which Xenons cannot do. I replaced the stock 55W H-7 with 70W bulbs which made a noticeable difference. I also tried a pair of 55W SilverStars and removed them since the 70W bulbs were superior. Roger Ellingson/Seattle
