HB4 Bulbs: The Complete UK Buyer's Guide
HB4 bulbs, also commonly known as 9006 bulbs, are widely used in automotive headlight and auxiliary-lighting systems. Depending on the vehicle and lamp unit, HB4/9006 bulbs can be used for dipped beam, low beam, main beam, high beam and front fog-light applications.
HB4 bulbs use the P22d base and are commonly associated with the 9006 reference. Argo Automotive Lighting offers three HB4 variants: 80W xenon white, 100W white/xenon-effect and 6000K white LED. This gives customers a choice between strong filament-style white light and modern LED illumination.
Because HB4/9006 is used across many different makes and lamp designs, the actual function can vary from vehicle to vehicle. On one vehicle it may be used as a dipped-beam or low-beam bulb, while on another it may be used for main beam, high beam or front fog-light duty. Always check the original bulb and lamp position before ordering.
This guide explains HB4 vs 9006, P22d fitment, 80W and 100W xenon-effect options, 6000K LED, headlight and fog-light applications, dipped beam vs main beam, HB4 vs HB3, HB4A terminology, and important heat and electrical-load considerations.
Quick Answer
An HB4 bulb is an automotive headlight and auxiliary-lighting bulb also widely known as 9006. It uses a P22d base and is commonly found in dipped-beam, low-beam and front fog-light applications, although selected vehicles may use HB4/9006 in other front-lighting positions.
Argo supplies HB4/9006 in 80W xenon white, 100W white/xenon-effect and 6000K white LED versions.
At a Glance
| Feature | HB4 / 9006 Bulbs |
|---|---|
| Main Bulb Type | HB4 |
| Common Reference | 9006 |
| Base | P22d |
| Traditional Reference | 12V 51W commonly associated with standard HB4 |
| Argo Xenon White | 80W |
| Argo White / Xenon-Effect | 100W |
| Argo LED | 6000K white |
| Argo Standard Halogen | Not currently sold |
| Main Applications | Dipped beam, low beam, main beam, high beam and front fog lights where specified |
Table of Contents
- What Is an HB4 Bulb?
- Are HB4 and 9006 the Same?
- What Does P22d Mean?
- What Is HB4A?
- Where Are HB4 / 9006 Bulbs Used?
- HB4 Headlight Bulbs
- HB4 Dipped Beam / Low Beam Bulbs
- HB4 Main Beam / High Beam Bulbs
- HB4 Fog Light Bulbs
- HB4 Front Fog Light Bulbs
- HB4 80W Xenon White Bulbs
- HB4 100W White / Xenon-Effect Bulbs
- HB4 6000K LED Bulbs
- LED vs Xenon-Effect vs Standard Halogen
- 80W vs 100W HB4 Bulbs
- Heat and Electrical Load
- HB4 vs HB3 / 9006 vs 9005
- How to Identify an HB4 / 9006 Bulb
- How to Replace an HB4 Bulb
- Common Mistakes
- Frequently Asked Questions
- Conclusion
What Is an HB4 Bulb?
HB4 is a single-filament automotive bulb fitting widely used in headlight and auxiliary-lighting systems. It is commonly known by the reference 9006.
The bulb uses a keyed P22d plastic base with a two-pin electrical connector and twist-lock fitment.
Is HB4 a Headlight Bulb?
Yes. HB4/9006 is commonly used as a headlight bulb, particularly in dipped-beam and low-beam applications. It is also used in selected front fog-light and other auxiliary-lighting positions.
💡 Argo Expert Tip
Do not assume HB4 always means dipped beam. The same fitting can be used in different lamp positions depending on the vehicle and lamp design.
Are HB4 and 9006 the Same?
Yes. HB4 and 9006 are commonly used to describe the same bulb family.
This is why product listings may use phrases such as:
- HB4 bulbs
- HB4 LED bulbs
- HB4 headlight bulbs
- 9006 bulbs
- 9006 headlight bulbs
- HB4 9006 LED bulbs
- 9006 LED bulbs
- HB4 xenon bulbs
- HB4 white bulbs
- 9006 white bulbs
Why Are There Two Names?
HB4 is the bulb-family designation, while 9006 is the commonly used SAE-style reference. In automotive retail, both names are widely used.
What Does P22d Mean?
P22d is the base designation associated with HB4/9006 bulbs. It refers to the keyed mounting base and connector arrangement that locks into the headlamp or fog-lamp housing.
💡 Argo Expert Tip
If the base tabs do not line up correctly, do not force the bulb. Similar-looking bulb families can use different keying.
What Is HB4A?
HB4A is a related automotive bulb reference that can appear in searches and cross-reference listings. It should not automatically be assumed to be identical to every standard HB4/9006 application.
When the original vehicle specifies HB4A, compare the original bulb, base keying and connector carefully before substituting a standard HB4/9006 bulb.
Where Are HB4 / 9006 Bulbs Used?
Depending on the vehicle and lamp assembly, HB4/9006 bulbs can be used for:
- Headlight bulbs
- Dipped beam bulbs
- Dipped headlight bulbs
- Low beam bulbs
- Low beam headlight bulbs
- Main beam bulbs
- High beam bulbs
- Fog light bulbs
- Foglight bulbs
- Fog lamp bulbs
- LED fog light bulbs
- Front fog light bulbs
- LED fog lamp applications
- Other auxiliary front-lighting positions
HB4 Headlight Bulbs
HB4 headlight bulbs are widely used in front headlamp systems. They are particularly common in dipped-beam and low-beam positions, although fitment varies by vehicle.
Customers searching for headlight bulbs, headlight bulb replacement, headlight replacement or LED headlight bulbs should always confirm that HB4/9006 is the actual fitting required.
HB4 LED Headlight Bulbs
Argo's 6000K white HB4 LED option provides a modern cool-white appearance in compatible headlamp units.
HB4 Dipped Beam / Low Beam Bulbs
Dipped beam bulbs and low beam bulbs provide the normal forward-driving beam used at night and in poor visibility when other traffic is present.
HB4/9006 is widely associated with low-beam and dipped-beam applications, which is why terms such as dipped headlight bulbs and low beam headlight bulb are highly relevant to this fitting.
What Is the Difference Between Dipped Beam and Low Beam?
In everyday terminology, dipped beam and low beam generally refer to the same headlight function.
💡 Argo Expert Tip
If your vehicle uses HB4 for dipped beam, replace both sides as a matching pair where possible so colour and appearance remain consistent.
HB4 Main Beam / High Beam Bulbs
Selected vehicles use HB4/9006 in main beam or high beam positions.
Main beam projects light further down the road and is used when there is no risk of dazzling other road users.
What Is the Difference Between High Beam and Main Beam?
In UK terminology, main beam and high beam generally refer to the same headlight function.
HB4 Fog Light Bulbs
Fog light bulbs, foglight bulbs and fog lamp bulbs are another important application group for HB4/9006.
Some vehicles use HB4 bulbs in low-mounted fog lamps rather than in the main headlamp unit.
LED Fog Light Bulbs
Argo's 6000K white HB4 LED can be used in compatible LED fog light bulb applications where the lamp is designed for HB4/9006.
HB4 Front Fog Light Bulbs
HB4/9006 is widely used as a front fog light bulb in selected vehicles.
Front fog lamps are mounted lower than the main headlamps and are intended for poor-weather and auxiliary-lighting use.
LED Fog Lamp Applications
Where an HB4/9006 lamp uses a compatible LED replacement, the 6000K white output gives a clean modern appearance.
HB4 80W Xenon White Bulbs
Argo offers an HB4 80W xenon white bulb for customers who want a whiter-looking filament-style light.
This option produces a cleaner white appearance compared with traditional warm halogen-style output.
Are HB4 Xenon White Bulbs HID?
No. Xenon white describes the appearance of the light and does not mean the bulb is a true HID xenon discharge lamp.
HB4 100W White / Xenon-Effect Bulbs
Argo also offers an HB4 100W white / xenon-effect bulb.
The higher wattage can produce stronger output than lower-wattage filament bulbs, but it also creates more heat and places greater electrical load on the vehicle wiring and lamp housing.
Important 100W Warning
Do not assume a 100W bulb is suitable simply because it fits the P22d holder. Check the original wattage, wiring, connector and lamp housing first.
HB4 6000K LED Bulbs
HB4 LED bulbs use light-emitting diodes instead of a traditional filament.
Argo's HB4 LED option produces a modern 6000K cool-white output.
Benefits of HB4 LED Bulbs
- Modern cool-white appearance
- Instant illumination
- Lower electrical consumption than high-wattage filament bulbs
- Long operating life
- Suitable for compatible headlight and fog-light applications
LED Size and Cooling
LED bulbs may use heat sinks, fans or additional electronics, so rear clearance should be checked before fitting.
LED vs Xenon-Effect vs Standard Halogen
| Feature | 6000K LED | 80W / 100W Xenon-Effect | Standard Halogen |
|---|---|---|---|
| Technology | LED | Filament / xenon-effect | Filament |
| Colour | Cool white | Whiter appearance | Warm white |
| Electrical Load | Generally lower | Higher at 80W/100W | Traditional specification |
| Heat | Managed through heat sink/fan where applicable | Higher | Moderate |
| Argo Range | Yes | Yes | No standard halogen currently |
Standard halogen remains useful as a comparison because the traditional HB4 specification is commonly associated with 12V 51W, even though Argo's current HB4 range focuses on xenon-effect and LED alternatives.
80W vs 100W HB4 Bulbs
| Feature | 80W HB4 | 100W HB4 |
|---|---|---|
| Electrical Load | High | Higher |
| Heat Output | High | Very high |
| Wiring Stress | Higher than standard | Higher still |
| Argo Option | Xenon white | White / xenon-effect |
💡 Argo Expert Tip
If the vehicle originally specifies a standard-wattage HB4, do not move to an 80W or 100W bulb without checking the electrical system and lamp housing.
Heat and Electrical Load
High-wattage filament bulbs draw more current and produce more heat.
Potential issues from unsuitable high-wattage bulbs include:
- Overheated connectors
- Damaged wiring
- Discoloured reflectors
- Melted plastic housings
- Blown fuses
LED Heat Management
LED bulbs consume less electrical power than 80W or 100W filament bulbs, but high-output LEDs still generate heat and may rely on heat sinks or cooling fans.
HB4 vs HB3 / 9006 vs 9005
HB4/9006 is commonly confused with HB3/9005 because they look similar.
They are different bulb families and should not be treated as directly interchangeable.
| Feature | HB4 / 9006 | HB3 / 9005 |
|---|---|---|
| Common Reference | 9006 | 9005 |
| Base | P22d | P20d |
| Common Use | Low beam / fog where specified | High beam / auxiliary where specified |
| Interchangeable? | No | No |
💡 Argo Expert Tip
Always compare the base tabs and connector before ordering. HB3 and HB4 can look very similar in photographs.
How to Identify an HB4 / 9006 Bulb
Look for:
- HB4 marking
- 9006 reference
- P22d base
- Two-pin connector
- Twist-lock keyed plastic base
How to Replace an HB4 Bulb
1. Switch Off the Vehicle
Turn off the ignition and lighting circuit.
2. Allow the Bulb to Cool
High-wattage filament bulbs can become extremely hot.
3. Access the Headlamp or Fog-Lamp Housing
Access may be from the engine bay, wheel arch or rear of the lamp unit depending on the vehicle.
4. Disconnect the Electrical Plug
Release the connector carefully.
5. Twist and Remove the Bulb
HB4/9006 bulbs normally use a twist-lock fitting.
6. Fit the Replacement
Align the P22d locating tabs correctly and secure the bulb.
7. Reconnect and Test
Check operation before refitting covers or trim.
Common Mistakes When Buying HB4 Bulbs
Confusing HB4 with HB3
HB4/9006 and HB3/9005 are similar-looking but different bulb families.
Assuming HB4 Is Always Low Beam
HB4 is commonly used for dipped beam and low beam, but selected vehicles use it in other positions.
Assuming Xenon White Means HID
Xenon-effect filament bulbs are not true HID discharge bulbs.
Choosing 80W or 100W Without Checking Wiring
Higher-wattage bulbs place greater electrical and thermal load on the lamp system.
Assuming LED Will Fit Any Housing
LED heat sinks and fans can require additional rear clearance.
Ignoring the P22d Base
Similar-looking bulbs may use different keyed bases.
Assuming HB4A Is Automatically the Same
HB4A is a related reference, but the original bulb and base should be checked before substitution.
💡 Argo Expert Tip
Before ordering, check five things: HB4/9006 reference, P22d base, lamp position, original wattage and available space.
Frequently Asked Questions
What is an HB4 bulb?
HB4 is an automotive headlight and auxiliary-lighting bulb also commonly known as 9006.
Is HB4 the same as 9006?
Yes. HB4 and 9006 are commonly used to describe the same bulb family.
What base does HB4 use?
HB4/9006 uses the P22d base.
What is HB4 used for?
HB4 can be used for dipped beam, low beam, main beam, high beam and front fog-light applications depending on the vehicle.
Is HB4 a dipped-beam bulb?
HB4 is commonly used for dipped beam/low beam, but not exclusively.
Can HB4 be used for main beam?
Yes, on selected vehicles where the lamp unit specifies HB4/9006.
Can HB4 be used for fog lights?
Yes. Front fog lights are a common HB4/9006 application.
Does Argo sell HB4 halogen bulbs?
No. Argo's current HB4 range focuses on xenon-effect and LED options.
Does Argo sell HB4 xenon bulbs?
Yes. Argo offers HB4 80W xenon white and 100W white/xenon-effect bulbs.
Does Argo sell HB4 LED bulbs?
Yes. Argo offers HB4 LED bulbs in 6000K white.
What colour is 6000K HB4 LED?
6000K is a cool white colour.
What is the standard HB4 wattage?
The traditional HB4/9006 specification is commonly associated with 12V 51W.
Are HB4 xenon white bulbs HID?
No. Xenon white describes the appearance of a filament-style bulb and is not the same as a true HID system.
What is the difference between HB4 and HB3?
HB4 is commonly referenced as 9006 with a P22d base, while HB3 is commonly 9005 with a P20d base. They are not directly interchangeable.
What is HB4A?
HB4A is a related bulb reference. Check the original bulb, base keying and connector before substituting a standard HB4/9006 bulb.
Can I replace HB4 with LED?
Only where the lamp, available space, electrical system and applicable road-use requirements are suitable for the LED replacement.
Are 80W and 100W HB4 bulbs safe?
They are only suitable where the lamp housing, connector and wiring can safely handle the increased electrical load and heat.
Is HB4 a 12V bulb?
HB4/9006 is commonly used in 12V passenger-vehicle lighting systems.
Can HB4 bulbs be used as headlight replacements?
Yes, where the vehicle specifies HB4/9006 in that headlight position.
Conclusion
HB4 bulbs, also known as 9006 bulbs, are widely used across headlight and auxiliary-lighting systems.
They use the P22d base and can be found in dipped beam, low beam, main beam, high beam and front fog-light applications depending on the vehicle.
Argo Automotive Lighting offers three HB4 variants: 80W xenon white, 100W white/xenon-effect and 6000K white LED.
Before buying, always verify the HB4/9006 reference, P22d base, lamp position, original wattage and available space.
Explore Argo Automotive Lighting's range of HB4 bulbs for compatible headlight and fog-light applications.
Free UK delivery on every order.