580 Bulbs: The Complete UK Buyer's Guide
580 bulbs are versatile automotive wedge bulbs used across a wide range of vehicle lighting applications. Also known as T20 bulbs, 7443 bulbs, W21/5W bulbs and W3x16q bulbs, they are commonly found in compatible daytime running lights, brake and tail lights, rear fog lights, reverse lights and some indicator applications.
One reason 580 bulbs cause so much confusion is that they look extremely similar to 582 bulbs. Both belong to the T20-style wedge family, but they are not the same bulb. A traditional 580 is a W21/5W dual-filament, dual-intensity bulb commonly cross-referenced as 7443, while a 582 is a W21W single-filament, single-intensity bulb commonly cross-referenced as 7440.
580 bulbs are available in several technologies and colours, including traditional filament bulbs, xenon-effect white bulbs and LED versions in white, red and amber. The correct version depends on the application, vehicle, lamp housing and electrical system.
Throughout this guide, Argo Automotive Lighting explains what a 580 bulb is, how T20 and 7443 references relate to it, the difference between 580 and 582 bulbs, where different 580 bulb colours are used, LED and CANBUS considerations, and how to choose the correct replacement for your vehicle.
Quick Answer
A 580 bulb is a dual-intensity automotive wedge bulb commonly designated W21/5W. It is also widely known as a T20 bulb or 7443 bulb and uses a W3x16q wedge base. A conventional 580 bulb normally operates at 12V with 21W and 5W filaments, allowing two brightness levels where the vehicle uses both circuits.
A 580 should not be confused with a 582 / W21W / 7440 bulb. The 582 is a single-intensity bulb and uses a different W3x16d base/contact arrangement.
At a Glance
UK Bulb Reference: 580
ECE / Common Designation: W21/5W
Common Alternative Names: 580, T20, 7443, W21/5W
Base: W3x16q
Traditional Voltage: 12V
Traditional Wattage: 21/5W
Traditional Design: Dual filament / dual intensity
Common Technologies: Filament, xenon-effect and LED
Common LED Colours: White, red and amber
Possible Applications: DRL, brake/tail, rear fog, reverse/backup and indicator applications where the vehicle specifies 580/W21/5W
Commonly Confused With: 582 / W21W / 7440
Table of Contents
- What Is a 580 Bulb?
- What Are T20 and 7443 Bulbs?
- 580 vs 582 Bulbs: What's the Difference?
- Where Are 580 Bulbs Used?
- 580 Bulbs for Daytime Running Lights
- Fiat 500 Daytime Running Light Bulbs
- 580 Brake and Tail Light Bulbs
- 580 Reverse and Backup Light Bulbs
- 580 Rear Fog Light Bulbs
- 580 Indicator Bulbs
- 580 Filament Bulbs Explained
- 580 Xenon-Effect Bulbs Explained
- 580 LED Bulbs Explained
- 580 CANBUS LED Bulbs and Dashboard Warnings
- Choosing the Correct Bulb Colour
- How to Identify a 580 W21/5W Bulb
- How to Replace a 580 Bulb
- Common Mistakes When Buying 580 Bulbs
- Frequently Asked Questions
- Conclusion
What Is a 580 Bulb?
A 580 bulb is a T20-style glass wedge automotive bulb commonly designated W21/5W. Traditional 580 bulbs normally operate on a 12V vehicle electrical system and contain two filaments rated at 21W and 5W.
The two-filament design allows the bulb to provide two different light intensities when the vehicle and lamp holder are wired to use both circuits. This is particularly useful in combined lighting functions such as stop and tail applications, where one bulb can operate at a lower intensity for the tail light and a higher intensity when the brake pedal is pressed.
What Does W21/5W Mean?
W21/5W describes the two traditional filament wattages:
- 21W for the higher-intensity circuit.
- 5W for the lower-intensity circuit.
The exact way those circuits are used depends on the vehicle and lamp assembly.
What Base Does a 580 Bulb Use?
A traditional W21/5W 580 bulb uses a W3x16q wedge base. Unlike a metal bayonet bulb, the glass wedge section pushes into a compatible T20-style bulb holder.
💡 Argo Expert Tip
If you can see two separate filaments inside your original glass bulb and the bulb is marked W21/5W, it is a strong indication that you are looking at a 580/7443-type bulb. Always confirm the base and vehicle specification as well.
⚠️ Common Mistake
Do not assume that every T20 bulb is a 580. The visually similar 582/W21W/7440 is a single-intensity bulb with a different base/contact arrangement.
What Are T20 and 7443 Bulbs?
Automotive bulbs often have several names, and the 580 is a perfect example.
You may see the same general bulb family described as:
- 580 bulb
- T20 bulb
- 7443 bulb
- W21/5W bulb
- W3x16q bulb
What Does T20 Mean?
T20 is a commonly used description for this larger automotive wedge-bulb format. However, T20 alone does not tell you whether the bulb is the dual-intensity 7443/580 type or the single-intensity 7440/582 type.
What Is a 7443 Bulb?
7443 is a widely used cross-reference for the dual-intensity T20 W21/5W bulb family. In the UK, the same type is commonly referred to as a 580 bulb.
Is a 580 Bulb the Same as a 7443?
580 and 7443 are commonly used references for the same W21/5W dual-intensity bulb family. As always, confirm the physical base and original bulb specification before installation.
💡 Argo Expert Tip
When searching for a replacement, use more than one reference. Searching for 580, W21/5W and 7443 can help you compare the correct bulb family while avoiding the similar 582/7440 type.
580 vs 582 Bulbs: What's the Difference?
This is one of the most important sections in this guide because 580 and 582 bulbs are regularly confused. They are both T20-style wedge bulbs and can look almost identical when held side by side, but their electrical design and base/contact arrangements are different.
| Feature | 580 Bulb | 582 Bulb |
|---|---|---|
| Bulb Designation | W21/5W | W21W |
| Common US Reference | 7443 | 7440 |
| Traditional Filaments | Two | One |
| Intensity | Dual intensity | Single intensity |
| Traditional Wattage | 21/5W | 21W |
| Base | W3x16q | W3x16d |
Why Do 580 and 582 Bulbs Look So Similar?
Both bulbs use the same general T20-style wedge format and have very similar external dimensions. The key differences are in the internal filament/circuit arrangement and the contacts at the wedge base.
How Can I Tell a 580 from a 582?
On a conventional clear filament bulb, look through the glass:
- A 580 / W21/5W / 7443 normally has two filaments.
- A 582 / W21W / 7440 normally has one filament.
Then check the markings and base. The 580 uses W3x16q, while the 582 uses W3x16d.
Can You Fit a 582 Where a 580 Is Required?
You should use the bulb type specified for the vehicle. Although the bulbs look similar, a 582 is single-intensity and does not provide the same two-circuit function as a 580. The base/contact arrangements are also different.
Can You Fit a 580 Where a 582 Is Required?
Again, use the specified bulb. A 580 is designed as a dual-intensity W21/5W bulb and should not be assumed to be an interchangeable replacement for a W21W/582 socket.
💡 Argo Expert Tip
If a customer says, “the bulb looks exactly the same”, check the filament count, markings and contacts before doing anything else. The visual similarity between 580 and 582 is one of the biggest causes of incorrect orders.
⚠️ Common Mistake
580 = 7443 = W21/5W.
582 = 7440 = W21W.
They are related T20-style bulbs, but they are not the same bulb.
Where Are 580 Bulbs Used?
580 bulbs are used across several automotive lighting functions, but the exact application depends on the vehicle and the bulb technology or colour selected.
Compatible applications can include:
- Daytime running lights (DRLs).
- Brake and stop lights.
- Tail lights.
- Reverse lights and backup lights.
- Rear fog lights.
- Front indicators.
- Rear indicators.
- Direction indicators and turn signal lights.
Not every 580 bulb colour or technology is suitable for every application. A white LED intended for a reverse light, for example, is not the same choice as an amber LED intended for an indicator or a red LED intended for a stop/tail application.
Why Does the Same Bulb Fitment Have So Many Uses?
The 580 describes the physical/electrical bulb family rather than one single lighting position. Vehicle manufacturers can use the same W21/5W fitting in different lamp assemblies.
💡 Argo Expert Tip
Always match fitment + colour + application. Getting only the 580/T20/7443 fitting correct is not enough if the bulb output colour is wrong for the lamp.
580 Bulbs for Daytime Running Lights
One of the most common searches for this bulb family is for daytime running light bulbs, often shortened to DRL bulbs.
580 bulbs are fitted as daytime running lights on a number of compatible vehicles. Depending on the vehicle, the dual-intensity design may allow the lamp to operate differently under different lighting conditions.
580 Halogen DRL Bulbs
A standard filament 580 W21/5W bulb provides a straightforward replacement where the vehicle was designed for a traditional 12V 21/5W bulb.
580 Xenon-Effect DRL Bulbs
Xenon-effect 580 bulbs are still filament-based replacement bulbs rather than HID xenon lamps. They are designed to produce a whiter-looking light than a conventional clear filament bulb and are most relevant to white-light applications such as DRLs and, where specified, reversing lights.
580 LED DRL Bulbs
White 580 LED bulbs are a popular upgrade for compatible DRL applications. They can produce a crisp white appearance and use less electrical power than the original 21/5W filament design.
💡 Argo Expert Tip
If upgrading a DRL from filament to LED, check the bulb's physical dimensions as well as its electrical compatibility. Some high-output LED designs are larger than the original glass bulb.
⚠️ Common Mistake
Do not assume that every white T20 LED is automatically suitable for a vehicle simply because it fits the socket. Check dual-intensity operation, dashboard monitoring and available space inside the lamp.
Fiat 500 Daytime Running Light Bulbs
Fiat 500 daytime running light bulbs are a particularly common search because the Fiat 500 is well known for using replaceable DRL bulbs on many versions.
Depending on model year and lamp specification, a compatible 580/T20/W21/5W bulb may be used for the daytime running light function. However, Fiat 500 lighting specifications can vary, so you should always verify the original bulb or vehicle fitment before ordering.
What Should I Check on a Fiat 500?
- Model year.
- Original bulb markings.
- Whether the existing bulb is W21/5W / 580 / 7443.
- Whether you want a standard filament, xenon-effect or compatible LED replacement.
- Whether the vehicle reports bulb-failure warnings after an LED upgrade.
💡 Argo Expert Tip
For a Fiat 500 DRL replacement, do not buy purely from the words “Fiat 500 bulb”. Confirm the exact W21/5W/580 fitment because different lighting positions and model variations can use different bulb types.
580 Brake and Tail Light Bulbs
Because a traditional 580 is a dual-intensity W21/5W bulb, it is particularly suited to compatible combined brake light and tail light applications.
The lower-intensity circuit can be used for the tail light, while the higher-intensity circuit can be used for the brake/stop function where the lamp assembly is designed that way.
Red 580 LED Brake Light Bulbs
Red 580 LED bulbs are available for compatible stop and tail applications. A red LED can be particularly appropriate where the lamp design requires or benefits from a red light source.
Can White 580 Bulbs Be Used Behind a Red Lens?
Some lamp clusters create the required red output using the lens itself, so a clear/white filament bulb may be specified as original equipment. With LED conversions, colour interaction with the lens can be different, so choose a bulb colour suitable for the specific lamp design and required final light output.
Brake Light Bulb Replacement
When replacing a brake/tail bulb, test both lighting levels after installation:
- Switch on the sidelights/tail lights and check the lower-intensity function.
- Press the brake pedal and check the higher-intensity stop-light function.
💡 Argo Expert Tip
If a newly fitted 580 works as a tail light but not as a brake light, or vice versa, check that the vehicle genuinely requires a dual-circuit 580/7443 bulb and that both contacts in the holder are clean and making contact.
580 Reverse and Backup Light Bulbs
Some compatible vehicles use the T20/580-style fitting in reverse light bulbs, also known as reversing light bulbs or backup light bulbs.
For reverse applications, white light output is normally required, so relevant options can include clear filament bulbs, xenon-effect white bulbs and white LED bulbs where compatible with the vehicle.
Why Choose White LED Reverse Light Bulbs?
A compatible white LED replacement can provide a crisp white appearance and strong illumination. However, the bulb must still fit physically inside the lamp and operate correctly with the vehicle's electrical system.
Xenon-Effect Reverse Bulbs
Xenon-effect filament bulbs can offer a whiter appearance without converting to LED technology. They are not HID xenon lamps; they remain direct-replacement filament bulbs.
💡 Argo Expert Tip
For reversing applications, check light distribution as well as headline brightness. The bulb needs to illuminate the reflector effectively, not simply look bright when viewed directly.
580 Rear Fog Light Bulbs
A 580 fitment may also appear in compatible rear fog light applications. Rear fog lamps must produce the correct red output, so the lamp design and bulb colour matter.
Traditional clear filament bulbs may be used behind a red lens where specified by the manufacturer. For LED replacements, a red LED may be preferable in some lamp designs, but the correct choice depends on the cluster.
💡 Argo Expert Tip
Do not use a xenon-effect white bulb simply because it fits a rear fog socket. Rear fog applications require the correct final red light output.
580 Indicator Bulbs
Some vehicles use 580/T20/7443 bulbs in compatible indicator bulb applications.
For an indicator application, the final light must be the correct amber/orange colour. This may be achieved using an amber bulb in a clear lamp housing or by the lamp lens itself, depending on the vehicle design.
Amber 580 LED Indicator Bulbs
Amber 580 LED indicator bulbs are available for compatible front and rear indicator applications. They may also be described using phrases such as:
- Orange indicator bulbs.
- Rear indicator bulbs.
- Front indicator bulbs.
- Car indicator bulbs.
- Direction indicators.
- Turn signal lights.
LED Indicators and Hyperflashing
Traditional indicator systems often monitor electrical load. Because LED bulbs draw less power than filament bulbs, some vehicles may flash too quickly or report a bulb fault after an LED conversion.
Vehicle Hazard Lights
Where the same indicator bulbs are used by the vehicle's hazard warning system, they will also flash when the hazard lights are activated.
💡 Argo Expert Tip
After fitting amber 580 LEDs, test the left indicators, right indicators and hazard lights. Check the flash rate and dashboard for warnings before refitting any difficult trim.
580 Filament Bulbs Explained
Traditional 580 bulbs use two tungsten filaments inside a glass envelope. The standard W21/5W specification provides two brightness levels and remains the simplest replacement where the vehicle was originally designed for a conventional filament bulb.
Advantages of Traditional 580 Bulbs
- Direct replacement for compatible original equipment.
- Correct traditional 21/5W electrical load.
- Dual-filament operation.
- No LED conversion required.
- Works with the reflector and lamp design intended for a filament bulb.
Where Can Filament 580 Bulbs Be Used?
The correct traditional 580 bulb can be used wherever the vehicle manufacturer specifies W21/5W/580, subject to the colour and lamp design required for that position.
💡 Argo Expert Tip
If you simply want the closest replacement to the original bulb and do not want to deal with possible LED warning issues, a standard W21/5W filament bulb is usually the most straightforward option.
580 Xenon-Effect Bulbs Explained
580 xenon-effect bulbs are filament bulbs designed to produce a whiter-looking light than a standard clear filament bulb. They are sometimes marketed as xenon white bulbs, but they should not be confused with HID xenon discharge systems.
Best Applications for Xenon-Effect 580 Bulbs
They are most logically suited to applications where a white output is required, such as compatible:
- Daytime running lights.
- Reverse lights.
- Backup lights.
They are not the natural choice for amber indicator applications or red stop/tail/rear-fog applications unless the lamp housing itself is designed to produce the correct final colour and the bulb is suitable for that position.
💡 Argo Expert Tip
Think of xenon-effect 580 bulbs as a filament-based white-light styling upgrade, not as a replacement for every colour/application in the 580 family.
580 LED Bulbs Explained
580 LED bulbs are available in many different designs, using surface-mount LEDs or other LED configurations around the bulb body.
Common search references include:
- 580 LED bulbs.
- T20 LED bulbs.
- 7443 LED bulbs.
- W21/5W LED bulbs.
White 580 LED Bulbs
White versions are commonly chosen for compatible DRL and reversing applications.
Red 580 LED Bulbs
Red versions are intended for compatible brake, stop, tail and rear-fog applications where red output is appropriate.
Amber 580 LED Bulbs
Amber versions are intended for compatible indicator and turn-signal applications.
Dual-Intensity LED Operation
A correctly designed 7443/580 LED replacement can provide two electrical operating levels to replicate the dual-intensity function of a traditional W21/5W bulb. Check the product specification because not every T20 LED is a dual-intensity 7443 design.
💡 Argo Expert Tip
Do not confuse a 7443 LED with a 7440 LED. Just as with conventional 580 and 582 bulbs, one is intended for dual-circuit operation and the other for single-circuit operation.
580 CANBUS LED Bulbs and Dashboard Warnings
Some 580 LED products include additional electronics intended to improve compatibility with vehicles that monitor bulb operation. These are often described as CANBUS LED bulbs or error-reducing/error-free LED bulbs.
What Does CANBUS Mean on an LED Bulb?
In automotive bulb listings, CANBUS usually refers to an LED design with additional circuitry intended to reduce bulb-failure warnings or other compatibility issues on monitored lighting systems.
Does CANBUS Guarantee No Warning?
No LED bulb can be assumed to work without warnings on every vehicle. Monitoring thresholds and electrical systems vary between manufacturers, models and model years.
Possible LED Compatibility Symptoms
- Dashboard bulb warning.
- Fast flashing in indicator applications.
- Flickering.
- Bulb remaining faintly illuminated.
- One of the dual-intensity functions not operating as expected.
💡 Argo Expert Tip
CANBUS compatibility should be treated as a vehicle-specific compatibility feature, not as a guarantee that one LED bulb will behave identically on every car.
⚠️ Common Mistake
Do not buy a 7440/582 single-intensity CANBUS LED when your vehicle requires a 7443/580 dual-intensity bulb simply because both products are described as T20.
Choosing the Correct Bulb Colour
The correct 580 bulb colour depends on the function and the design of the lamp cluster.
White Bulbs
White bulbs are commonly relevant to:
- Daytime running lights.
- Reverse lights.
- Backup lights.
Red Bulbs
Red LED bulbs can be used in compatible:
- Brake lights.
- Stop lights.
- Tail lights.
- Rear fog lights.
Amber Bulbs
Amber/orange LED bulbs are intended for compatible:
- Front indicators.
- Rear indicators.
- Direction indicators.
- Turn signals.
What About Traditional Clear Filament Bulbs?
A clear traditional bulb can serve different lighting functions when the lamp cluster itself provides the required colour. Always follow the original lamp specification.
💡 Argo Expert Tip
The bulb fitting tells you whether it physically/electrically belongs to the 580 family. The application and lamp design tell you what colour output you need.
How to Identify a 580 W21/5W Bulb
If you have the original bulb in your hand, there are several useful checks.
Check the Markings
Look for references such as:
- 580
- W21/5W
- 7443
- 12V 21/5W
Look for Two Filaments
On a traditional clear bulb, a 580 will normally have two visible filaments because it is a dual-intensity bulb.
Inspect the Wedge Base
The 580 uses the W3x16q base. Compare the contact layout with the original bulb rather than relying on the external glass shape alone.
Compare with a 582
If you are unsure whether the bulb is a 580 or 582:
- 580: W21/5W, 7443, dual filament, W3x16q.
- 582: W21W, 7440, single filament, W3x16d.
💡 Argo Expert Tip
Take a clear photo of the original bulb markings and base before disposing of it. This can make identifying a replacement much easier if the numbers are difficult to remember later.
How to Replace a 580 Bulb
The exact replacement procedure varies by vehicle and lighting position, so consult the vehicle handbook when necessary.
Before You Begin
- Park safely and switch off the ignition.
- Turn off the relevant exterior lights.
- Allow a hot filament bulb to cool.
- Confirm you have the correct 580/W21/5W replacement.
- Confirm the correct colour for the application.
Remove the Bulb Holder
Access may be through the engine bay, rear lamp cluster, boot trim, wheel arch or a dedicated access panel depending on the vehicle.
Remove the Old Wedge Bulb
Many T20 wedge bulbs pull directly from the holder once the holder has been removed. Do not use excessive force; check the vehicle instructions if access is difficult.
Compare Old and New Bulbs
Before fitting, compare:
- Bulb reference.
- Wedge contact arrangement.
- Overall size.
- Colour.
- Dual-intensity design where required.
Install and Test
Fit the bulb securely, reinstall the holder and test every relevant lighting function. For a brake/tail application, test both intensity levels. For an LED indicator, check flash rate and dashboard warnings.
💡 Argo Expert Tip
Test an LED replacement before reassembling difficult trim. If you discover a compatibility issue, you can resolve it without taking the lamp apart twice.
Common Mistakes When Buying 580 Bulbs
Confusing 580 with 582
This is the biggest mistake. A 580 is W21/5W/7443 and dual intensity. A 582 is W21W/7440 and single intensity.
Searching for T20 Without Checking 7443 or 7440
T20 describes the general wedge-bulb family. You still need to know whether the vehicle requires the dual-intensity or single-intensity version.
Ignoring Bulb Colour
A white LED, red LED and amber LED can all share the 580 fitment but are intended for different lighting functions.
Assuming Every LED Is Dual Intensity
Some T20 LED products are 7440/single-intensity designs. A vehicle that requires 580/7443 dual operation needs a suitable dual-circuit replacement.
Assuming CANBUS Means Universal Compatibility
CANBUS or error-reducing LEDs can improve compatibility, but vehicle monitoring systems differ.
Using Xenon-Effect White Bulbs for Coloured Functions
Xenon-effect white bulbs are most relevant to white-light applications. Do not use them where the final required output should be amber or red unless the vehicle's lamp design specifically provides that colour and the bulb is appropriate.
Buying Only by Vehicle Model
Lighting fitments can change with model year, trim and lamp design. Always verify the original bulb.
Forgetting to Test Both Filament Functions
On a dual-function stop/tail installation, a bulb can appear to work while one circuit is not operating. Test both.
💡 Argo Expert Tip
For a 580 bulb, check five things: 580/W21/5W/7443 reference, W3x16q base, dual-intensity requirement, bulb colour and application.
Frequently Asked Questions
What is a 580 bulb?
A 580 bulb is a T20-style automotive wedge bulb commonly designated W21/5W. Traditional versions are dual-filament 12V 21/5W bulbs and use a W3x16q base.
Is a 580 bulb the same as a 7443?
580 and 7443 are commonly used references for the same dual-intensity W21/5W T20 bulb family.
Is a 580 bulb a T20 bulb?
Yes. The 580 belongs to the T20-style wedge family. However, T20 also includes similar single-intensity bulb types, so check whether you need 7443/580 or 7440/582.
What does W21/5W mean?
W21/5W refers to the traditional dual-filament specification: a 21W higher-intensity filament and a 5W lower-intensity filament.
Is a 580 bulb dual filament?
A traditional filament 580/W21/5W bulb has two filaments and provides two intensity levels. LED replacements use electronic circuits rather than literal filaments but should provide the appropriate dual-intensity functionality where specified.
What is the difference between a 580 and 582 bulb?
A 580 is W21/5W / 7443 / dual intensity / W3x16q. A 582 is W21W / 7440 / single intensity / W3x16d. They look very similar but are not the same bulb.
Are 580 and 582 bulbs interchangeable?
They should not be assumed to be interchangeable. They use different electrical/contact arrangements and provide different functions.
What is the difference between 7443 and 7440?
7443 is the dual-intensity type commonly associated with 580/W21/5W, while 7440 is the single-intensity type commonly associated with 582/W21W.
What base does a 580 bulb use?
A conventional 580/W21/5W bulb uses a W3x16q wedge base.
What base does a 582 bulb use?
A conventional 582/W21W bulb uses a W3x16d wedge base.
Can 580 bulbs be used as daytime running light bulbs?
Yes, 580/W21/5W bulbs are used in compatible daytime running light applications where the vehicle manufacturer specifies this fitting.
Are 580 bulbs used in a Fiat 500?
580/W21/5W bulbs are commonly associated with compatible Fiat 500 daytime running light bulb applications, but fitment can vary by model year and lamp specification. Always verify the original bulb before ordering.
Can 580 bulbs be used as brake light bulbs?
Yes, the dual-intensity W21/5W design is used in compatible brake/stop and tail-light applications.
Can 580 bulbs be used as tail light bulbs?
Yes, where the vehicle uses a 580/W21/5W dual-function stop/tail arrangement.
Can 580 bulbs be used as reverse light bulbs?
Some vehicles use a 580/T20-style fitting for reversing applications. Confirm the exact bulb specification and use the appropriate white-output bulb.
Can 580 bulbs be used as rear fog light bulbs?
Some compatible vehicles may use this fitting in a rear fog application. The finished lamp must provide the correct red output, so the lamp design and bulb colour are important.
Can 580 bulbs be used as indicator bulbs?
Yes, some vehicles use 580/T20/7443 fitments for front or rear indicators. For a clear indicator housing, an amber/orange bulb is normally required to produce the correct indicator colour.
What colour 580 LED bulb do I need for indicators?
Amber/orange 580 LED bulbs are intended for compatible indicator applications where the bulb itself needs to provide the amber output.
What colour 580 LED bulb do I need for brake lights?
Red LEDs are commonly used for compatible stop/tail applications, although some lamp assemblies are designed around a clear/white bulb behind a red lens. Match the vehicle's lamp design.
Can I replace a 580 filament bulb with an LED?
A compatible dual-intensity 7443/580 LED can replace a filament bulb in many applications, but check physical size, electrical compatibility, dashboard monitoring and required colour.
What is a CANBUS 580 LED bulb?
It is an LED replacement with additional electronics intended to improve compatibility with bulb-monitoring systems and reduce warning messages. Compatibility still varies by vehicle.
Why does my car show a bulb warning after fitting 580 LEDs?
LED bulbs normally draw less power than traditional 21/5W filament bulbs. Some vehicle monitoring systems interpret the lower electrical load as a failed bulb.
Why do my indicators flash quickly after fitting 580 LEDs?
The reduced electrical load of an LED can cause some indicator systems to hyperflash because the vehicle interprets the low load as a bulb failure.
Are xenon 580 bulbs actual HID xenon bulbs?
Products described as xenon white or xenon-effect 580 bulbs are normally filament-based styling bulbs designed to produce a whiter appearance. They are not HID xenon discharge lamps.
How do I know whether I need a 580 or 582?
Check the markings on the original bulb and inspect the filament/contact arrangement. Look for W21/5W, 580 or 7443 for the dual-intensity type, or W21W, 582 or 7440 for the single-intensity type.
Conclusion
580 bulbs are versatile T20-style automotive bulbs used across many compatible vehicle lighting systems. The key references to remember are 580, W21/5W, 7443 and W3x16q.
The traditional 580 is a dual-filament, dual-intensity 21/5W bulb, which is one of the main reasons it is used in applications where two light levels may be required. Modern replacement options include standard filament bulbs, xenon-effect white bulbs and LED versions in white, red and amber.
The most important distinction is between the 580 and 582. Although they are both T20-style wedge bulbs and can look almost identical, a 580 is the dual-intensity W21/5W/7443 type, while a 582 is the single-intensity W21W/7440 type. Checking this difference before ordering can prevent one of the most common T20 bulb mistakes.
When choosing a replacement, always match the bulb fitment, dual- or single-intensity requirement, colour, voltage, application and vehicle compatibility.
Explore Argo Automotive Lighting's range of daytime running light bulbs and indicator bulbs, including compatible 580/T20/7443 options in filament, xenon-effect and LED technologies.
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