168 VS. 194 Bulbs: Which is better for interior lights?
Introduction
When it comes to choosing light bulbs for automotive interior lighting, the 168 and 194 bulbs are often discussed and compared. Their similar appearance, size, and wedge-shaped base can pose challenges for many individuals trying to distinguish between the two and decide on the more suitable option especially they are interchangeable. This article aims to provide a detailed analysis of the variances between 168 and 194 bulbs, as well as addressing frequently asked questions about T10 and T15 bulbs. By reading this article, you can gain a comprehensive understanding of 168 and 194 light bulbs to help you make an informed decision.

Differences and similarities between 168 and 194 bulbs
This comparison table of similarities and differences below will quickly give you an idea of the differences between 168 and 194 bulbs.
Bulb Type | / | 168 | 194 |
---|---|---|---|
Differences | Power Rating | 4.9W | 3.8W |
Brightness | Higher brightness | Lower brighter | |
Light Output | Rated for 3 candles power | Rated for 2 candles power | |
Heat | Runs hotter, more heat | Less heat, safer to use | |
Lifespan | Average 1500H | Average 2500H | |
Brightness Adjust | Variety levels of brightness | One level of brightness | |
Application | Interior lighting and some exterior lighting | Interior lighting | |
Similarities | Base Design | Wedge-type base | |
Compatibility | Interchangeable |
From the comparison table above, we can know that the main differences between them are wattage and performance. The followings are detailed analysis of their differences.
168 VS. 194
- Watts
The biggest distinction between the two bulbs was their wattage. The 168 bulbs are rated at 4.9 watts, while the 194 bulbs are rated at 3.8 watts. Due to different wattages, their brightness levels are also different.
- Brightness (Light Output)
As mentioned above, the higher the wattage, the brighter the bulb. The 168 bulb is rated at a higher wattage than the 194, which corresponds to a slightly higher light output than the 194. This indicates that the 168 bulb is brighter than the 194. We can compare that under the same conditions 168 is rated to be 3 candles and 194 is rated to be 2 candles. Therefore the 168 bulb can provide wider lighting coverage than the 194 bulb.
- Heat
Because of their wattage and light output, 168 bulbs will run hotter and produce more heat than 194 bulbs. However, there is no need to worry too much about the possibility of the 168 bulb melting the surrounding components due to its operating temperature. In fact, the difference in operating heat between the two is not great, only that the 194 bulb will be safer to use than the 168 bulb. As long as it is in the case of appropriate use, 168 bulbs are also stable and safe.
(Warming Tips: Considering the impact of heat on bulbs, it's valuable to explore methods of heat dissipation. For more information, you can read this blog - THE IMPORTANCE OF HEAT DISSIPATION IN AUTOMOTIVE LED HEADLIGHT BULBS)
- Lifespan
The average life of 168 bulbs is generally 1500H, while the average life of 194 bulbs is generally 2500H, which is also the advantage that 194 bulbs in comparison.
- Brightness Control
The 168 bulb is designed with different brightness levels, so you can freely adjust the brightness of the bulb according to the ambient light condition. This is because the 168 bulb has two support wires, which allow it to change the voltage to increase or decrease the brightness of the bulb. The 194 bulb has only one support wire and therefore has a single brightness level and cannot adjust the brightness level of the light.
- Applications
While both 168 and 194 bulbs are suitable for vehicle interior lighting and can be used interchangeably, they have specific applications that differ. The 168 bulb, being brighter and covering a wider area, is often used for both interior and exterior lighting, including dome lights, reading lights, dashboard lights, as well as vehicle side marker lights and license plate lights. On the other hand, the 194 bulb is generally preferred for interior lighting, especially in dome lights, trunk lights, glove compartment lights, and vanity lights, thanks to its stable continuous lighting characteristics and lower heat generation.
After explaining their differences in detail, further exploration of the 168 and 194 will help you better understand these two models. Before that, we might as well take a brief look at the definition of T10 bulbs.
What is T10?
Light bulbs come in many varieties, the most common being T bulbs (tubular bulbs) and incandescent bulbs (globular bulbs). And T10 is a type of T bulb, the T stands for tubular, and the 10 stands for a tubular bulb with a diameter of 10mm which is 1.25 inches. They are widely used in vehicle interior lighting and some exterior lighting like license plate light. It also have several equivalent crossover models, which include 194, 168, 158, 161, 2825, 193, 192, and so on.
What is 168 and its applications?
The 168 bulb falls under the T10 bulb category, sharing the incandescent filament structure and wedge-shaped mounting base with the T10 bulb. Its distinctive features include higher wattage, increased brightness and light output, and the ability to adjust brightness levels, making it ideal for indoor lighting. Common applications include dome lights, reading lights, and dashboard lights, but its brightness and wide coverage also make it suitable for some exterior lighting, such as vehicle side marker lights and license plate lights.
What is 194 and its applications?
Similar to the 168, the 194 bulb is a T10 bulb variant with an incandescent filament structure and wedge-shaped mounting base. However, it differs in wattage and light output. The 194 bulb is well-suited for indoor lighting in areas like dome lights, trunk lights, glove compartment lights, and vanity lights. It maintains a single brightness level, providing stable continuous lighting with low heat generation and an extended lifespan.
In summary, both the 168 and 194 bulbs belong to the T10 bulb category, renowned for interior lighting installations. Choosing between them depends on your specific needs. If you're looking for higher brightness and wider coverage, the 168 bulb might be preferable. However, the 194 bulb, with lower wattage and a longer lifespan, is a reliable choice for various interior lighting scenarios.
Conclusion
Whether you choose 168, 194 or T10 bulbs, please pay attention to the voltage compatibility and vehicle suitability of the vehicle installation location. Fortunately, T10 LED bulbs offer a versatile solution, eliminating the need to choose between 168 and 194, providing enhanced brightness and longevity, making them a worthwhile investment for your vehicle's interior lighting needs.
If you want to know about the style selection and installation of T10 LED bulbs, please read this article - UPGRADING YOUR CAR'S INTERIOR LIGHTS: A GUIDE TO LED OPTIONS, INSTALLATION, AND MORE
FAQ
Q: Can you use a 194 bulb in place of a 168?
A: Yes. They both belong to the T10 category and have similar bases and construction, so they can be used interchangeably.
Q: Are 168 and 2825 the same?
A: They both have the same base type and are used in the same applications. The only difference is their wattage and brightness output.
Q: Where can I use T10 bulbs?
A: T10 LED light bulbs could be used in cars or trucks dome lights, map lights, parking lights, door courtesy lights, license plate lights, trunk cargo lights, side marker lights, etc. But it depends on whether the factory settings of your vehicle model in these applications are T10-size bulbs or not.
Q: What is W5W and T10?
A: The designation "W5W" is derived from the bulb's specifications. The "W" stands for "Wedge," indicating the type of base, while the "5" represents the base size in millimeters. W5W and T10 are both the same type of bulbs and have similar uses, especially in vehicle interior lighting. In fact, the W5W bulb can be considered a type of T10 specification, where 5W refers to its power.
Q: What’s the difference between T10 and T15 (T10 VS. T15)?
A: The biggest difference between them is the size and they are not interchangeable. Because their sizes are inconsistent, T15 bulbs are larger than T10 bulbs, and T15 cannot be installed in a T10 socket. Under extreme conditions, the T10 can be reluctantly installed in a T15 socket, but this may result in a reduction in light output and reduced performance. The focus of applications is also different. T10 bulbs are usually used for dashboard lights and interior lights, while T15 bulbs are usually used for backup lights.
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