The 3157 and 3156 bulbs are some of the most common halogen bulbs you’ll find in modern vehicles, especially for rear lighting. If you’re thinking about upgrading your lighting setup or just want to know what these bulbs are all about, this guide will walk you through the basics—from compatibility and performance to buying tips and upgrades.

If you’re looking for a more direct comparison, we’ve also put together detailed guides you can check out:

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

3157 vs. 7443 Bulbs: Key Differences

3057 vs. 3157: Key Differences

What Is Bulb Compatibility for 3157 3156?

Both the 3157 and 3156 bulbs are widely used in vehicles made by Ford, Chevrolet, Volkswagen, Acura, Toyota, and plenty of others.

The 3157 is a dual-filament bulb, which means it can handle two brightness levels in a single unit. That’s why you’ll see it in places like tail lights/brake lights, and turn signals where the bulb needs to switch between “dim” and “bright” modes.

The 3156 is a little simpler. It’s a single-filament bulb, so it’s generally used for functions that only need one brightness level, such as reverse lights or certain turn signals. Even though the 3156 and 3157 look almost identical, they aren’t always interchangeable because their bases and wiring requirements are different.

Each bulb also has cross-reference numbers that may come in handy when shopping for replacements. The 3157 can substitute for part numbers including 3155, 3457A, 3457NA, 4057, 4157, 3157A, 3057A, 3157NA, 5702A, 4157NA, 3057, 3454NA, 4157, 3047, 3357A, 3757A, 3457, 4114, and 3357. There are also less common variants like 4114LL, 3457K, 3157LL, 4157K, 3057LL, 4157NAK, 3357LL, 4057LL, 3157K, and 3357K.

The 3156 crosses over with numbers like 3456, 3156A, 3156AK, 3156ST, 3156K, 3156LL, and 3456LL.

The safest bet, though, is to check your owner’s manual or use a car bulb finder tool to make sure you’re getting the right fit.

What Is the Base Type of a 3157 3156 Bulb?

Both bulbs use a wedge-style base that slides into the socket. The 3157 has a dual-contact wedge base, labeled W2.5×16q, to support its two filaments. The 3156 has a single-contact wedge base, called W2.5×16d.

That small difference makes a big impact on how and where they can be used.

How Much Light Does a 3157 3156 Bulb Produce?

Brightness depends on whether you’re using the stock incandescent version or a modern LED replacement. A standard 3156 incandescent bulb puts out around 402 lumens. The 3157, with its two filaments, has a “bright” mode that’s also about 402 lumens and a “dim” mode that drops down to around 38 lumens, which is just enough for tail lights.

If you step up to LEDs, the numbers climb quickly. A high-quality 3156 or 3157 LED from SEALIGHT can put out as much as 1,800 lumens, giving you a serious visibility boost compared to factory bulbs.

What Is the Wattage of a 3157 3156 Bulb?

A 3156 bulb typically draws about 27 watts at 12.8 volts. The 3157 has two wattage ratings because of its dual-filament design: about 27 watts for the bright filament and around 7 watts for the dim one. That split is what allows it to work as both a running light and a brake or signal light.

What Is the Bulb Lifespan of 3157 3156?

Traditional incandescent bulbs usually last somewhere between 1,000 and 2,000 hours, which works fine but means you’ll eventually need replacements. LED upgrades, on the other hand, can last 30,000 hours or more.

That’s why so many drivers switch to LEDs. it’s less hassle over time and saves you from constantly swapping bulbs.

Where Is a 3157 3156 Bulb Installed?

You’ll find these bulbs mainly in the rear lighting assembly of your car. Common spots include tail lights, running lights, brake lights, and turn signals. The 3157, thanks to its dual-filament setup, sometimes doubles as a reverse light depending on the vehicle’s wiring. To be sure, check your owner’s manual before ordering replacements.

Are 3156 3157 LED Bulbs Worth It?

For most drivers, the answer is yes. LEDs bring several big advantages: they last up to 10–15 times longer than incandescent bulbs, shine brighter, draw less power, and light up instantly. That “instant-on” feature might sound minor, but for brake lights and turn signals, it means other drivers see your signals a split second sooner, which can actually prevent accidents.

If you’re aiming for the brightest, most efficient upgrade, SEALIGHT’s 3156 and 3157 LEDs are a solid choice.

Where to Buy 3156 3157 LED Bulbs?

You can pick up both 3156 and 3157 LED bulbs directly from SEALIGHT. As America’s #1 aftermarket automotive lighting brand, SEALIGHT offers a full range of products—from headlights and fog lights to tail lights, brake lights, turn signals, and interior bulbs.

We offer a one-stop solution backed by R&D, manufacturing, and reliable customer support, so you can shop with confidence knowing your upgrade will fit and perform the way it should. Shop today!