Originally Posted by TrueNorth
Factory fogs have plastic housing, plastic reflector and plastic lens.
Even with heavy gauge wiring you run the risk of melting them.
Might consider an aftermarket driving light in the same location all together or run some auxillary lighting on your bumper to add the extra light.
Originally Posted by dcoy
Thanks everyone! I think I am going to go bo9roadking's suggested route!
TrueNorth makes a good point about the stock plastic fog lights. If you do wire the higher wattage bulbs off the battery, keep an eye on your fogs to make sure you don't melt them.
You may have to go with an aftermarket fog light. Some people are going to the LED lights, but I couldn't find a set of LED lights that I liked for fogs. I ditched the plastic fogs and replaced them with halogen Hella 90mm Foglamps that have a glass lens, metal reflector, and metal housing (Susquehanna MotorSports - Auto Performance Product
). The Hellas can be purchased from several places, but I went with Rallylights because they can also build a custom wiring harness for you that connects to the battery and has a relay to connect to your factory fog light switch.
I had to fabricate a bracket for the Hellas because the holes in the fogs mounting points didn't match up with my aftermarket bumper, but they work great and I don't have to worry about melting anything. The Hellas are bright enough that I can drive down the road with my headlights off and the fogs provide enough light that it looks like I have my headlights on. The Hella fogs are standard equipment for a mercedes cls55 amg.