I installed the Bosch H4 headlights with the 100/55 watt bulbs, I think that was the number. They were the highest wattage available anyways. These lights are incredible. You can't believe the light they throw and with the Z beam you rarely get any "complaints". Absolutely buy these headlights, a friend has been purchasing the Chinese knock offs and those work nice also, but I like to have the Bosch name on my headlight. Hella also makes the same thing. At first, on this site some thought the original wiring may not be up to the task. But, I have had them several years now with many nightime hours with no problems in my 230SL.