If 3157 bulbs are dual-element, why are they used in the DRL's, which only have one setting? If I'm not mistaken, dual-element bulbs are for signaling lights which are serve as running lights when not signaling.

The reason I ask is I would like get LED DRL's, but I've read on here they don't last long (on the order of minutes). What if 3156 bulbs are used instead?

 

just cause lol, i have been running 3157's for over a year and haven't had any issues. gm is weird, even the reverse bulbs and turn signals are 3157 but only light at one brightness. i have tried 3156 at first in my drls, but the burned out in a day.

 

I believe the answer I got while working at the Chevy dealer was,

1-just because

2-the 3157 bulb has a higher output rating then the single filament bulb of the same style.

 

I'm curious if this is why 3157 LED bulbs burn out in the DRL's so quickly.

 

I have had LEDs in my drls for a year now 3157 type and they have done fine! I also used the same bulbs in the reverse lights.

 

Do you have a link to where you got them?

 

DRLs should actually be a 4114 from what I've seen. 3157s will work as its the same style but its not listed as the OE bulb. They burn out constantly though, I never replaced mine when they burned out.

 

x2^ Ive always used 3157's ambers becuase they just look brighter IMO never had any problems with mine.

 

Superbrightled's says that their 3156 are okay for GM DRL's while 3157 are not. I think I will get some amber LED 3156's from them and see how they work. I've only had one regular 3157 DRL bulb burn out in the 4.5 years I've had the truck

 

I sell them...which are same ones in my truck! 4114 Is the stock bulb but cross references to the 3157. Superbrightleds has various types of 3157s as in how many LEDs you want and wattage and style. I have sold mine to tons of ppl here on the cost and not one problem except one that got stepped on and he tried saying it came smashed like that...lol...and some ppl not knowing they they have to be positive and negative!