I own a 2006 Ram 3500 4 door long bed, I notice two of the tail light brake lights and turn signal bulbs weren't burning correctly so I removed them to replace them and found one # 3057 in one socket and one 3157 in the other on the passenger side, the driver side had two 3057 in both sockets
I'm wonder why
My owner manual calls for 3057 in both tail lights, brake lights and turn signal sockets
Any one know the differences in them
Thanks in advance for any help on this
Cab

3157 is slightly brighter on the park filament. Why they make so many is just confusing. I would use what it calls for. Most people find a bulb that fits and plug it in.

I think that's the same bulb my GMC uses. When one burnt out earlier this year the only one I could find in the store was the opposite as what it came with but it worked with no problems.
The factory bulb had double filaments on the same post on one side but there was no visual difference when it was lit.

I did a little research on them, as already said they are near the same and will fit in the tail lights and turn signals on my truck, the 3157 uses a little more current so it is a tiny bit brighter
I'll stick with the 3057 OEM bulbs for now