Trying to figure out the right light bulb size for your car's interior? If you’re shopping for replacements, you’ve probably come across numbers like T10, 194, and 168. They’re among the most common wedge-base bulbs used in vehicle's interior lighting, like dome lights, map lights, vanity mirrors, trunk lights, and more.

In this guide, we’ll walk through the main characteristics of these bulbs, and whether upgrading to LEDs is worth it for your car.

If you’re more interested in a side-by-side comparison, we also have a detailed guide that breaks down the differences: T10 vs 194 vs 168 Bulb.

what are 194 t10 168 bulbs

What Is Bulb Compatibility for 194, T10, 168?

A big source of confusion with automotive bulbs is the sheer number of part numbers and “cross reference” equivalents. The good news is that 194, T10, and 168 bulbs are highly compatible thanks to their shared wedge base design. Here’s what you need to know about their interchangeability and the other numbers you might see:

Cross Reference Numbers

These bulbs often go by many names, including but not limited to:

T10, T12, T15, 194, 175, 168, #555, 2886X, 194R, 161B, 3652, 193, 658, 2827, 194NA, 161, 558, 168NA, 2825, 194G, 160, 168A, 192, 2821, 194B, 158, W5WB, 579, 168, 2825ST, 168ST, 3652LL, 579LL, 2825LL, 168NALL, 2825L, 2821LL, 168LL, 194ST, 161LL, 194NALL, 2827LL, 158LL, 194LL, 906NA, 917, 906, 916NA, 904NA, 922, 916, 904, 921, 912, 920, 921K, 916LL, 921LL, 912LL, 920LL, 917LL, 906LL, 916NALL, 904LL, and 921ST.

Can You Replace 194 with 168 or T10 (or Vice Versa)?

For the most part, yes. As long as the socket is the same (W2.1x9.5d), the bulb physically fits, and the voltage matches your car’s 12V system, you can swap between them without trouble. The main differences come down to wattage and brightness.

It’s always a good idea to double-check your owner’s manual or the markings on the old bulb, or use an online car bulb finder before ordering, just to be sure.

What Is the Base Type of a 194, T10, 168 Bulb?

All three bulbs share the same base: W2.1x9.5d. That technical code simply describes the dimensions of the wedge that slides into the socket, which is 2.1 mm wide and 9.5 mm long. Because the base is standardized, these bulbs can be swapped around in a wide range of interior and exterior lighting spots.

What Are the Different Types of 194, T10, 168 Bulbs?

194 T10 168 bulbs mainly come in two types: incandescent (traditional) and LED alternatives.

Traditional incandescent bulbs have been around forever. They use a tiny tungsten filament that glows when electricity passes through it, giving off that classic warm, yellowish light. They’re cheap, easy to find, and still common in many cars today.

Then you’ve got LED versions, which have become the go-to upgrade. LEDs are much brighter for their size, they draw way less power, and they can produce everything from crisp white light to bold colors.

No matter the type, always make sure the new bulb matches your socket and fits the available space in your light fixture.

What Is the Lifespan of a 194, T10, 168 Bulb?

The lifespan really comes down to the type of bulb you’re using.

Traditional incandescent or halogen versions, like the standard 194, 168, or T10 wedge bulbs, usually last somewhere between 1,000 and 2,500 hours under normal use. That might mean replacing them every year or two,

194 T10 168 LED replacements, on the other hand, can run for 30,000 to 50,000 hours if they’re built well. Many drivers report going several years without having to swap them once.

What Is the Voltage and Wattage of a 194, T10, 168 Bulb?

All three operate on a 12V system, which is standard in cars. The wattage is where they vary a little: a 194 uses about 4 watts, a T10 around 3.8 watts, and a 168 closer to 5 watts. The higher wattage of the 168 makes it slightly brighter, which is why it’s often used where a little more light output is needed.

How Much Light Does a 194, T10, 168 Bulb Produce?

If you’re sticking with incandescent bulbs, expect about 25–40 lumens of output. That’s enough for small applications like license plate lights or interior courtesy lamps, but it’s not exactly dazzling.

LED replacements change the game. Quality 194/168/T10 LED bulbs can reach up to 1200 lumens. The exact brightness depends on the design and how many diodes are packed into the bulb, but overall LEDs give you far more usable light with less energy.

Are 194, T10, 168 LED Bulbs Worth It?

Yes. They're one of the easiest and most rewarding upgrades you can make. LEDs give your car a clean, modern look while making it easier to see inside at night. They also sip power compared to incandescents, which keeps wiring and housings cooler. And because they last so much longer, you’ll save yourself the hassle of crawling into the cabin every few months to replace a burnt-out bulb.

Plenty of drivers on forums and review sites mention that once they swapped to LEDs, they never went back. It’s not just about looks, it’s also about convenience and long-term value.

Where to Buy 194, T10, 168 LED Bulbs?

You’ll find these bulbs everywhere online, but it pays to stick with a trusted brand. Cheaper options might look appealing, but they often flicker, run hot, or burn out way too fast. Look for features like CAN-bus compatibility if your car has a bulb-out warning system, and check reviews from other drivers with your make and model.

Quality bulbs also use proper heat sinks to keep everything cool and extend their lifespan. SEALIGHT is a top choice for many drivers, with a reputation for quality and excellent customer support. When shopping for upgrades, consider these 194 168 T10 LED options from SEALIGHT.

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