3175 vs 4057 bulbs

[ath627]

What's the difference between a 3157 and 4057 bulb? I installed SilverStar 3157's in my front turn signals. Prior to doing so, I tested these bulbs in my tail lights, and they worked, even though the book says they're supposed to be 4057's.

I'm curious about the difference between these two bulbs, as I'd like to upgrade the tails to SilverStars if there's no real difference.

I also installed SS 921's in my backup lights, and they're much brighter than OEM bulbs.

[08stang40]

http://www.donsbulbs.com/cgi-bin/r/b...-life~usa.html


http://www.donsbulbs.com/cgi-bin/r/b...0.48a~usa.html

Besides a few specs being slightly different, The shape and base are the same, but looks like one is a dual filament.

[ath627]

So with the exception of the filaments, there doesn't seem to be much of a major difference between the two bulbs. So I could use 3157's in place of the 4057's in the tail lights.

[08stang40]

No I think the dual filament is so when you have your lights on and you hit the brakes the lights get brighter so drivers know you are slowing down.

[ath627]

Originally Posted by 08stang40

No I think the dual filament is so when you have your lights on and you hit the brakes the lights get brighter so drivers know you are slowing down.

Isn't that exactly how the lights are supposed to function?

[08stang40]

Originally Posted by ath627

Isn't that exactly how the lights are supposed to function?

What is was trying to say is that you have to have a dual filament in your tail lamps.. so as ling as the bulb you are putting back there is a dual filament you should be OK.

[ath627]

Originally Posted by 08stang40

What is was trying to say is that you have to have a dual filament in your tail lamps.. so as ling as the bulb you are putting back there is a dual filament you should be OK.

I still don't understand your point. The OEM bulb is the single-filament 4057 bulb.

However, I do think that there won't be a problem switching to the brighter, dual-filament 3157 SilverStar bulbs in the tails. They function identically to the 4057, and actually draw a little less current than the OEM 4057 bulbs.

[08stang40]

Originally Posted by ath627

I still don't understand your point. The OEM bulb is the single-filament 4057 bulb.

However, I do think that there won't be a problem switching to the brighter, dual-filament 3157 SilverStar bulbs in the tails. They function identically to the 4057, and actually draw a little less current than the OEM 4057 bulbs.

hmm mine are dual filaments in my 2008, and they have not been replaced. Sorry for any confusion. I just went out and looked at the bulbs in the assembly.

I did find this

http://allfordmustangs.com/forums/20...ight-bulb.html

[ath627]

Thanks for the clarification, Jim. I originally looked at the replacement guide on Sylvania's website, which said 4057 for the tail lights, which is the single-filiament bulb. However, I just looked at the 2008 Mustang owner's manual, and it say either 3057 or 4057. So I guess a single (4057) or double (3057) bulb will work. And the wattage/current/voltage specs on a 3157 bulb are identical to the 3057, so those will work too.

So I'm going to install 3157 SilverStar bulbs in the tails, and 921 SilverStars in the CHMSTL. I already have 921 SilverStars in the backup lights, and they're great.

[Nice Pony]

3057nand 4057 are both dual element bulbs...