Finding the correct bulb size for your vehicle's lighting can be confusing, especially when it comes to the similarly numbered 3156 and 3157 bulbs. Both 3156 and 3157 bulbs are commonly used for tail lights in many modern cars and trucks. What is the difference between them?

This article will focus on distinguishing 3156 vs 3157 bulbs to help you make an informed decision when shopping for car light bulbs.

3156 vs. 3157 Bulbs: What’s the Difference?

The main difference between 3156 and 3157 bulbs is their filament and wiring structure. A 3156 bulb is a single filament bulb with one wire in the socket, while a 3157 bulb is a dual filament bulb with double wires in the socket.

Check below for more details:

3156 vs 3157 Filament Difference

The filament is an integral part of any light bulb, and it's the component that produces light when heated by an electrical current.

Single Filament: 3156 Bulb

The 3156 bulb is a single filament bulb. This means it has one wire in the socket that heats up to produce light. The single filament design is typically used in applications where only one light function is required. For instance, a 3156 bulb could be used for turn signal lights or brake lights, but not for both.

Dual Filament: 3157 Bulb

On the other hand, the 3157 bulb is a dual filament bulb. It contains two wires in the socket, each responsible for producing light. The two-filament design makes the 3157 a dual-function lamp. A 3157 bulb can be used as both turn signal lights and daytime running lights.

3156 vs 3157 Wiring Structures

The wiring structure refers to how the bulb connects to the vehicle's electrical system.

Single Wire Structure: 3156 Bulb

The 3156 bulb, with its single filament, also has a single wire structure. Therefore, the 3156 bulb produces light at a fixed brightness level.

Double Wire Structure: 3157 Bulb

The 3157 bulb, with its dual filament, features a double-wire structure. This allows the bulb to provide two levels of brightness.

3156 vs 3157 Compatibility: Are They Interchangeable?

Can You Use a 3157 Bulb in a 3156 Socket?

Yes, you can. A 3157 bulb can indeed be used in a 3156 socket. You can consider a 3157 bulb is the dual filament option for the 3156 bulb. This means it'll work perfectly fine with full functionality of the 3156 bulb.

What About the Reverse? Can You Use a 3156 Bulb in a 3157 Socket?

No. A 3156 bulb cannot work in a 3157 socket. The reason is because the 3156 bulb is designed for single filament function, while the 3157 socket is designed to support dual filament bulbs, which have two brightness levels.

If you attempt to use a 3156 bulb in a 3157 socket, you won't be able to achieve the dual brightness levels that a 3157 socket is intended for.

3156 and 3157 Bulbs: Understanding the Basics

What is a 3156 Bulb and What It Is Used For?

A 3156 bulb is a type of incandescent light bulb that is commonly used in automotive auxiliary lighting. It features a single filament structure and a base type of W2.5x16d.

Specifications-wise, a 3156 bulb operates at a voltage of 12.8 volts and a wattage of 26.9 watts. It emits light at a color temperature of 2800K, As for the bulb's luminous flux, or the total amount of light emitted, is 402 lumens.

In terms of application, the 3156 bulb is most commonly used as turn signal lights, tail lights, brake lights, backup lights, and parking lights.

Check the following 3156 LED bulb collections:

3156 LED Back Up Light Bulbs

3156 LED Turn Signal Light Bulbs

What is a 3157 Bulb and What It Is Used For?

The 3157 bulb is also an incandescent light bulb that is often used as auxiliary lighting in cars.

It is a double filament bulb, which allows it to serve dual functions, such as being a brake light and a parking light simultaneously.

The 3157 bulb features a base type of W2.5x16q. It operates at two different voltages and wattages due to its dual filament structure: 12.8 volts and 26.9 watts for one filament, and 14 volts and 8.3 watts for the other.

Despite having double filaments, the 3157 bulb still emits light at the same color temperature as the 3156 bulb (2800 K). However, its luminosity differs based on the filament in use: it emits 402 lumens at 12.8 volts and 38 lumens at 14 volts.

The 3157 bulb can be used in turn signal lights, backup lights, brake lights, parking lights, and high brake lights, etc.

Below is a summary table comparing the 3156 vs. 3157 bulb.

*The information on the specifications of the 3156 and 3157 halogen bulbs comes from SYLVANIA.

Upgrade Your Ride with LED Bulbs

Switching from standard halogen bulbs to LEDs can make a world of difference in your vehicle's lighting. 3156 and 3157 LED bulbs offer superior brightness and visibility over traditional halogens. And LED bulbs light up quickly than halogens, making your drive safer.

In addition, LEDs emit more lumens per watt. So 3156 and 3157 LED bulbs shine brighter while using less energy. This increased efficiency also means the bulbs run cooler, reducing the risk of damage.

Looking for 3156 or 3157 LED bulbs? Check the options from SEALIGHT below: