The T10 bulb  is the most common size found in car and truck interiors today. However, there are many bulb sizes that light up your vehicle's interior, like 194, 168, T15, 912, and 921. Upgrading to LED interior bulbs can get confusing with all these numbers! In this article, we’ll break down the differences between the main bulb types - T10, 194, and 168. We’ll also discuss the T5 and T15 bulbs. Knowing your interior bulb types will make that LED upgrade smooth sailing.

T10 vs 194 vs 168 Bulbs

Differences and Similarities of T10 vs 194 vs 168

T10, 194, and 168 bulbs are all wedge-base bulbs that are commonly used for interior lighting in vehicles. They all utilize a wedge base, specifically the W2.1x9.5d, that snugly fits into their sockets. Their primary difference lies in the wattage. The T10 bulb consumes 3.8W, the 194 bulb uses 4W, and the 168 bulb takes up 5W.

Below are more details:

- Base: All three bulbs utilize the same wedge base to fit into their sockets. The base has dimensions of W2.1mm x 9.5mm. This standardized base allows the bulbs to be interchanged in many applications.

- Wattage:T10 bulbs are typically 3.8 watts. 194 bulbs are usually 4 watts. 168 bulbs tend to be 5 watts. The higher the wattage, the brighter the bulb.

- Construction: These halogen bulbs consist of a compact glass capsule mounted in a plastic wedge base. Within the capsule is a fine tungsten filament that glows white hot when electricity is applied.

- Applications: T10, 194, and 168 bulb can be used interchangeably in most vehicle interior lighting applications, like dome lights, map lights, vanity lights, trunk lights, and more. The 168 bulbs can also be used in some exterior lights.

So in summary, while T10, 194, 168 three wedge-base bulbs are very similar, the main differences come down to wattage and light output.

T10 halogen bulb

W5W Bulb Equivalents

The wedge-base W5W bulb joins the T10, 194, and 168 as a common interior light. Though all these bulbs share the same wedge base and incandescent filament, they differ in wattage.

The W5W has many crossover equivalents including the 194, 168, 147, 152, 158, 159, 161, 168, 194, 192, and 193.

So the W5W shares the exact specifications as the 168 bulb. That means you can interchange W5W and 168 bulbs, or replace both with T10 or 194 bulbs if needed.

However, there are some wattage and output exceptions to be aware of. If you are buying new halogen bulbs to replace, checking your owner's manual is always safest when unsure.

LED T10, 194, and 168 Bulbs

There are also LED replacement bulbs available with the T10, 194, and 168 bases. These are brighter, longer lasting, and more energy efficient than traditional incandescent bulbs.

LED T10, 194, and 168 replacement bulbs provide:

- 2-3 times more light output than incandescents

- 30,000 to 50,000 hour lifespan vs 30-50 hours

- 50-80% less power consumption

Many LED wedges bulbs are designed to be direct replacements for multiple part numbers like 194, 168, 2825, etc.

For example, if your owner's manual says to replace a burned out dome light with a 194 bulb, you can often use a T10 or 168 bulb without any issues.

The benefits of LEDs make them an excellent option for upgrading your car's dim incandescent interior lighting. Just make sure to get the properly sized wedge base to match your vehicle's sockets.

Decoding T5, T10, and T15 Mini Wedge Bulbs

You may also come across several sizes of wedge-base bulbs when working on your vehicle's lighting. Here's a quick guide to tell T5, T10, and T15 bulbs apart:

- T5 bulbs are the smallest of the three wedge bulbs. They are mostly used for instrument panel and gauge cluster lighting. They have limited variety, any T5 bulb will work fine.

- T10 bulbs are medium-sized. They're commonly used for interior lighting like map lights, vanity mirrors, and dome lights where a compact bulb is needed. You can choose from different wattages and LED for variety.

- T15 bulbs  are the largest wedge bulbs. Their extra surface area makes them ideal for exterior applications like cargo lighting, reverse lights, and license plate illumination that require maximum brightness. More variety available.

While all three share the same wedge base design, the T15 bulbs have a larger glass capsule than T10, and T10 is bigger than T5. This results in different light output.

T5, T10, and T15, Are They Interchangeble?

- T10 and T15 bulbs use the same wedge base. But T15 bulbs are too large to properly fit T10 sockets.

- T10 bulbs can physically fit into T15 sockets in a pinch, but light output may be reduced. So for best results, always match the exact bulb type to the socket.

T5, T10, and T15, Which LED Bulb Should You Choose?

LED replacement bulbs are much brighter than original incandescent bulbs. You may want to go for LED for better lighting.

When upgrading to LED, opt for the largest bulb that properly fits the socket. For example, choose a T15 LED over a T10 LED for a T15 socket. The increased size results in more LED chips, more lumens, and brighter light.

Just be sure not to force a bulb where it doesn't belong. With the right LED for the application, you'll enjoy superior visibility.

Conclusion

T10, 194, 168, W5W, and other wedge base bulbs may seem confusing, but they share many similarities. With the right socket base, they are often interchangeable regardless of part number. Choosing the highest quality and wattage LED replacement maximizes light output. Just be sure to get the proper physical size bulb for your vehicle's specific application. Follow your owner's manual or check the socket if unsure.