Difference between after market driving lights and fog lights?
 

Probly a dumb question, but ive been looking around for a set of fog lights to replace the half/half light setup in the bumper of my 2010 MC. So far my thoughts are to remove the oem housings and then mount a set of lights behind the holes. From what i can tell, the oem holes are 4" in diamter? Does anyone see a problem of mounting them like this? As long as i get a 4" diameter light?

I plan on hooking them up like my leds, independent of the headlights/ignition and just switch em on when i want. If i did want to tap into the headlights, is it a difficult task?

As for the topic question, all the ones in the 4" range state driving lights on the box. And come with a h3 bulb. I want to get either jdm or nokya yellow bulbs for the headlights and whatever i put in the bumper. H3 seems like a small bulb, would it be any help in inclement weather?

As long as you are willing to put up with the computer telling you that you have some sort of problem, I see no problem. the computer is pretty smart when it comes to knowing whether OEM lights are there or not. You may find someone who can rig up some sort of resistor circuit to trick the car into believing all is well.

But the bumper openings just beg for something better than the half-hearted fog lights that come from the factory. You'd think in the UK they would have need for something better, given their climate.

Let us know what you come up with -- lots of us have considered this idea.

BTW -- take a look at PIAA 510s. They come in a fog specific version and you have quite a range of bulb types -- 35 to 55 watt -- in a range of colors, and PIAA lens and reflector technology is at the top of the heap.

I dont have oem fogs, just the parking lights, i was planning on just leaving those behind the bumper to keep the computer happy. Or maybe just those dummy bulbs with the resistors built in. Ill have a look at those PIAAs

Here's a link to the PIAA website -- It shows the 510s to be 3 15/16th inches in diameter. I used them for a bit on my car but went to the larger 710s. The fogs should be very effective. The "covers" on the lights pop off easily. They are pretty ugly in my estimation, but probably are effective at deflecting stones and such. I don't use mine.

http://www.piaa.com/Lamps/Lamp-pages/510.html

3-15/16 x 4-7/16 shouldn't look too bad tho. Now i just have to decide the wide beam or narrow.. im going to be replacing the bulbs anyways, so im not worried about what bulb comes with which kit... although, what bulb type do each have? I didnt see any note about it, unless its just my android phone rendering wrong?

before my edit i asked if the grilles were removable, re-read and saw your comment about em.. yeah they definitely wouldnt look oem with piaa and black cage haha. Looks like ill see if my local custom auto place can order me up a set

Yes, the black grills are removable -- sorta like a cover with cutouts, the whole grill clips on the sides. easily removable. I suspect that the reason they made their covers like that is to protect the lights from idiots -- like me -- who turn the lights on and forget to remove the covers. I did that more times than once with my old Cibie lights.