Interchangeable Or No: 3156 vs 3157?

You decided to replace a bulb in your car and upon removing the old one, you realize that there are actually two types that could fit - a 3156 or a 3157. But which one should you choose?

The fact is that a 3157 bulb may be used to replace a 3156 lamp, but the latter can not replace the former. The 3157 light bulb is two-sided, meaning it can be used as a brake light, turn signal, or RDL. The 3156, on the other hand, is only a single-function bulb, typically used as a turn signal.

Don't worry, we're here to help clear things up. In this article, we'll be comparing the two types of bulbs side-by-side so you can make an informed decision.

Socket Compatibility

If you have a 3157 bulb in your car but accidentally bought a 3156, you'll be disappointed to know that 3156 bulbs cannot be fitted into a 3157 socket. That is because the pins on a 3156 are arranged in a different pattern than those of a 3157. The good news is that you can use a 3157 to replace a 3156, as the pin arrangement is the same for both bulbs.

The main distinction you'll notice between 3156 and 3157 bulbs is the number of filaments. More specifically, 3156 bulbs feature a single filament and 3157 bulbs have two. Consequently, the light output for the 3157 bulb is brighter and more visible, making it safer to drive at night. So, as you can see, the problem is not only in the socket compatibility, the amount of filaments also matters.

Now that we've gone over the basics, let's take a more in-depth look at each type of bulb.

3156 Bulbs

As we have already mentioned, these are single-filament bulbs that may be used as a turn signal or reversing light. This is because the filament is positioned horizontally in the bulb, allowing it to emit light in a 360-degree beam. Thanks to this design, 3156 bulbs are often used as marker lights, too.

They have one level of brightness which is why they are not recommended for use as a brake lights. The idea is that you need two different intensities of light- a dimmer one for when the brake is not engaged and a brighter one for when it is. And since 3156 bulbs can't provide that, they are not used as brake lights.

These lamps also have a few color options. Thus, the 3156 bulb is available in both clear and amber.

The pros of this lamp:

• Wide range of applications
• Can be used as a turn signal, marker light, or reversing light

The cons of this lamp:

• Not recommended for use as a brake light

3157 Bulbs

These double-filament light bulbs can be used as a turn signal, RDL, or brake light. The two filaments are positioned vertically in the bulb, one on top of the other. Thanks to this design, the light is emitted in a 90-degree beam.

The 3157 bulbs are dual-filament, which means they have two different intensities of light- one for when the brake is not engaged and one for when it is. The filament arrangement also allows for several color options. You have much more options than with the 3156 bulbs, and you can even find 3157 bulbs with a clear or amber color.

Now that we have gone over the key differences between these two types of bulbs, you should be able to make an informed decision about which one to choose. If you need a bulb for a turn signal or marker light, go with a 3156. And if you're looking for a brake light or RDL, opt for a 3157. Besides, they have 2 levels of brightness and that would be really beneficial if you are driving in the dark.

The pros of this bulb are:

• Several brightness levels
• Can be used as a brake light, RDL, or turn signal
• More color options

The cons of this bulb:

• May be difficult to find in some stores

Now that we have gone over the key differences between these two types of bulbs, you should be able to make an informed decision about which one to choose. If you need a bulb for a turn signal or marker light, go with a 3156. And if you're looking for a brake light or RDL, opt for a 3157.

Specifications Comparison

Brightness

When looking for a bulb that emits brighter light, 3157 bulbs are the better option. Generating crisp and clear light, they draw more power than 3156 bulbs due to an additional filament. However, unless you regularly carry a lumen meter with you (and one that is sensitive), it may be difficult to notice the brightness difference between the two types of bulbs.

Color Temperature

The proper color temperature is also an important consideration, especially if you are looking for a bulb to use as a turn signal or marker light. The standard range is between 2700K and 3200K, with the lower number indicating a warmer light. A whiter light is in the 4000K to 5000K range. 3156 bulbs emit a light that is in the 4000K to 5000K range, while 3157 bulbs have a color temperature of 2700K to 3200K.

Usability

3156 bulbs have weak filaments, so they can only be used as turn signals or reversing lights. In contrast, 3157 bulbs are brighter and more versatile; for example, they can be used as brake lights, turn signals, or even running lights which are visible during the day.

Colors Variety

3157 bulbs are the better option if you're looking for more variety in color. They offer improved reproduction and clarity compared to 3156 bulbs, which have fewer color options. So, in case you need a diversity of colors, you know which bulbs to choose.

Conclusion

3156 and 3157 bulbs are both popular choices when it comes to automotive lighting. However, there are some key differences between the two that you should be aware of before making your decision. If you need a bulb for a turn signal or marker light, go with a 3156. And if you're looking for a brake light or RDL, opt for a 3157. Thanks for reading and we hope this article was helpful!