It`s high time to replace the blown bulb in your auto and you`re standing in the store aisle wondering what the difference is between a 7440 and a 7443. Do you need to know? Not really, but we`ll tell you anyway!

Although the 7440 and 7443 are often used interchangeably because of their naming schemes, they serve different purposes. The various types of turn signal bulbs make them each more applicable to different vehicles. Your car uses them in entirely different areas.

Let`s dive deeper and figure out which is which, and when you should use each one.

Socket Compatibility

Although 7443 and 7440 bulbs appear similar, they are in fact different shapes and sizes. We have tested a number of options and found that 7443 bulbs can be used in 7440 sockets but not the other way around. That is because the 7440 bulb socket is narrower than the 7443. The reason for this design is to allow European vehicles to have a smaller turn signal light.

The socket compatibility affects the installation process as well. To install a 7443 in a 7440 socket, you may need to do some wiggling and pushing to get it to fit. In some cases, the bulb may not fit at all.

7440 Bulb Characteristics

The 7440 is a one-filament lamp that is commonly used as a turn signal, brake light, side marker lamp, and trunk or cargo area light. This lamp is meant to be used in rear turn signal lights because it has a blunt tip.

The brightness level is 3600 Lumens which is really bright. The light output of any bulb affects its lifespan; the more light output, the shorter its lifespan will be. The color temperature of this lamp is 5500 Kelvin which is close to pure white. So, in case a driver needs to see the brake light more clearly, this type of lamp is a good choice. With such characteristics, you will get a more visible and powerful light output.

With the wattage of 24.98 Watt you will get more light output and the power usage will be lower. Whenever you need a powerful light output, but with lower power usage, this is the lamp you should choose.

The pros of using this lamp:

• more visible light output
• brighter light output
• lower power usage.

The cons are as follows:

• shorter lifespan
• more expensive.

7443 Bulb Characteristics

The 7443 is a two-filament lamp that is commonly used as a front turn signal. This lamp has a pointed tip which makes it ideal for use in stop lights because it provides a clear and bright light output.

The brightness level is 3600 Lumens which is really bright. The light output of any bulb affects its lifespan; the more light output, the shorter its lifespan will be. The color temperature of this lamp is 6500 Kelvin and it is really close to pure white. Any driver who uses this type of lamp will get a more visible and powerful light output.

If a driver needs a powerful light output, but with lower power usage, this is the lamp he or she should choose. The wattage of this lamp is 25 Watt which will provide more light output and the power usage will be lower.

The pros of using this lamp are:

• a variety of application
• nominal power usage

The cons of this bulb include:

• low wattage indicating a low light output.

Characteristics Comparison

Specs	7440 bulb	7443 bulb
Base	W3×16d	W3×16q
Number of filaments	1	2
Applications	fog lights, tail lights, brake lights, and turn signals	DRL, Brake lights, tail lights, indicator lights
Nominal power	12 V: 21 W	12 V: 21 / 5 W
Cross compatibility	7441, 992, 7440, 7440ST, 7440AL, 7440LL, 7440A	7444NA, 7443, 7443ST, 7443LL

Brightness

The 7440 and 7443 lamps have the same brightness level of 3600 lumens. So, if you are looking for a bright light output, either of these bulbs will work great. However, still when the bulbs are different even with the same light output would have different effects.

The 7440 bulb has a blunt tip which makes it ideal for use in rear turn signal lights because it provides a clear and bright light output. The 7443 bulb has a pointed tip which makes it ideal for use in stop lights because it provides a clear and bright light output.

Filament Type

7440 bulbs only have one filament, while 7443 bulbs have two. You'll get slightly better illumination from a 7443 bulb because of the extra filament present.

Beam Type

When comparing 7440 and 7443 lamps, it is important to consider the beam type. The 7440 has a single beam, while the 7443 has a dual beam. The 7440 produces a focused light beam that is ideal for use in turn signals. The 7443 produces a wide light beam that is ideal for use in stoplights.

Applications

7443 and 7440 bulbs differ in their function as the former is meant to be used in front turn signal lights while the latter intended for use in rear turn signal lights. However, beyond that, they serve no other similarity purpose. In fact, additional sedans are able to use 7440 bulbs as reversing lights.

While 7443 bulbs can also be used for front parking lights, 7440 bulbs are less intense and can typically only be used as reversing lights. The difference in brightness is due to the fact that 7443 bulbs produce more light overall.

FAQs

What is a 7443 bulb used for?

Our selection of LED lamps will brighten your reverse lights while still conserving energy. These bulbs have a halogen-style design and use only a fourth of the power traditional reverse lightbulbs would require. In addition to being excellent replacements for parking or tail lights, these can also decorate your vehicle's interior.

What is a 7440 bulb used for?

If you're looking for a replacement car or truck bulb that is more durable than average, this is the perfect solution. With increased longevity, these bulbs can take a lot of road shock and vibration. Besides, they use less power, so your car battery will thank you. These are the ideal turn signal or brake light replacements for any car or truck.