HB3 Bulbs: The Complete UK Buyer’s Guide (2026)

HB3 Bulbs: The Complete UK Buyer’s Guide (2026)

04 September, 2026
HB3 bulbs buying guide image showing a car at night with LED white headlights, one halogen fog light and one xenon white fog light, with HB3 LED, xenon and halogen bulbs displayed in front.

HB3 Bulbs: The Complete UK Buyer's Guide

HB3 bulbs, also commonly known as 9005 bulbs, are widely used in automotive headlight and auxiliary-lighting systems. Depending on the vehicle and lamp unit, HB3/9005 bulbs can be used for main beam, high beam, dipped beam, low beam and front fog-light applications.

HB3 bulbs use the P20d base and are commonly associated with the 9005 reference. Argo Automotive Lighting offers three main HB3 variants: 100W halogen, 100W xenon white and 6000K white LED. This gives customers a choice between traditional halogen output, whiter xenon-effect styling and modern LED illumination.

Because HB3/9005 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 high-beam bulb, while on another it may be used for low beam, dipped beam or fog-light duty. Always check the original bulb and lamp position before ordering.

This guide explains HB3 vs 9005, P20d fitment, 100W halogen vs xenon white vs 6000K LED, headlight and fog-light applications, high beam vs dipped beam, heat and electrical-load considerations, and common confusion with related bulb families.

Quick Answer

An HB3 bulb is an automotive headlight and auxiliary-lighting bulb also widely known as 9005. It uses a P20d base and is commonly found in headlight systems as a main/high-beam bulb, although selected vehicles also use HB3/9005 for dipped beam, low beam or front fog lights.

Argo supplies HB3/9005 in 100W halogen, 100W xenon white and 6000K white LED versions.

At a Glance

Feature HB3 / 9005 Bulbs
Main Bulb Type HB3
Common Reference 9005
Base P20d
Argo Halogen 100W
Argo Xenon White 100W
Argo LED 6000K white
Main Applications High beam, main beam, dipped beam, low beam and front fog lights where specified
Vehicle Voltage Primarily 12V passenger-vehicle applications

Table of Contents

  1. What Is an HB3 Bulb?
  2. Are HB3 and 9005 the Same?
  3. What Does P20d Mean?
  4. Where Are HB3 / 9005 Bulbs Used?
  5. HB3 Headlight Bulbs
  6. HB3 High Beam / Main Beam Bulbs
  7. HB3 Dipped Beam / Low Beam Bulbs
  8. HB3 Front Fog Light Bulbs
  9. HB3 100W Halogen Bulbs
  10. HB3 100W Xenon White Bulbs
  11. HB3 6000K LED Bulbs
  12. Halogen vs Xenon-Effect vs LED
  13. 100W HB3 Bulbs: Heat and Electrical Load
  14. HB3 vs HB4 / 9005 vs 9006
  15. HB3 HID Terminology Explained
  16. How to Identify an HB3 / 9005 Bulb
  17. How to Replace an HB3 Bulb
  18. Common Mistakes
  19. Frequently Asked Questions
  20. Conclusion

What Is an HB3 Bulb?

HB3 is a single-filament automotive bulb fitting commonly used in headlight and auxiliary-lighting applications. It is widely known by the North American reference 9005.

The bulb uses a keyed P20d plastic base with a two-pin electrical connector and twist-lock fitment.

Is HB3 a Headlight Bulb?

Yes. HB3/9005 is commonly used as a headlight bulb, especially for high-beam and main-beam applications. However, exact function varies by vehicle and lamp unit.

💡 Argo Expert Tip

Do not assume HB3 always means high beam. Some vehicles use the same fitting for dipped beam, low beam or fog lights, so always check the lamp position.

Are HB3 and 9005 the Same?

Yes. HB3 and 9005 are commonly used to describe the same bulb family.

This is why product listings may use phrases such as:

  • HB3 bulbs
  • HB3 headlight bulbs
  • HB3 9005
  • 9005 bulbs
  • 9005 headlight bulbs
  • HB3 LED bulbs
  • 9005 LED bulbs
  • HB3 9005 LED bulbs

Why Are There Two Names?

HB3 is the common bulb-family designation, while 9005 is the widely used SAE-style reference. In everyday automotive retail, both names are used interchangeably.

What Does P20d Mean?

P20d is the base designation used by HB3/9005 bulbs. It refers to the keyed plastic mounting base and connector arrangement.

The base ensures the bulb sits in the correct position within the headlamp or fog-lamp housing.

💡 Argo Expert Tip

If the base does not line up with the lamp housing, do not force it. Similar bulb families can look close but use different keying.

Where Are HB3 / 9005 Bulbs Used?

Depending on the vehicle and lamp assembly, HB3/9005 bulbs can be used for:

  • Headlight bulbs
  • Main beam bulbs
  • High beam bulbs
  • Dipped beam bulbs
  • Low beam bulbs
  • Front fog light bulbs
  • Fog lamp bulbs
  • Other auxiliary front-lighting positions

HB3 Headlight Bulbs

HB3 headlight bulbs are widely used in front headlamp systems. In many vehicles they are used for the main/high beam, but some lamp systems use HB3/9005 in other positions.

Customers searching for headlight bulb replacement, headlight replacement or LED headlight bulbs should always confirm that HB3/9005 is the actual fitting required.

HB3 LED Headlight Bulbs

Argo's HB3 LED option produces a modern 6000K white light. LED replacements can offer a cleaner, whiter appearance compared with traditional halogen-style output.

HB3 High Beam / Main Beam Bulbs

High beam bulbs and main beam bulbs are one of the most common applications for HB3/9005.

Main beam is designed to project light further down the road when there is no risk of dazzling oncoming traffic.

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.

HB3 9005 Main Beam Bulbs

Where a vehicle specifies HB3/9005 for main beam, Argo offers halogen, xenon white and LED options.

HB3 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.

Although HB3 is most commonly associated with high beam, selected vehicles and lamp units use HB3/9005 for dipped or low-beam applications.

What Is the Difference Between Dipped Beam and Low Beam?

In everyday usage, dipped beam and low beam generally refer to the same function.

💡 Argo Expert Tip

Never choose a bulb position based only on the name HB3. Check whether your vehicle uses HB3 for main beam, dipped beam or another function.

HB3 Front Fog Light Bulbs

Selected vehicles use HB3/9005 as front fog light bulbs or fog lamp bulbs.

Fog lights are mounted lower than the main headlamps and are intended for poor-weather and auxiliary-lighting use.

HB3 LED Fog Light Bulbs

Argo's 6000K white LED HB3 can be used in compatible fog-light applications where the lamp is designed for HB3/9005.

HB3 100W Halogen Bulbs

Argo offers an HB3 100W halogen bulb for customers looking for a strong traditional filament-style light source.

A 100W bulb draws considerably more power and creates more heat than many standard-wattage headlight bulbs, so the lamp housing, connector and wiring must be suitable.

Advantages of HB3 100W Halogen

  • Traditional filament technology
  • Strong output
  • Simple direct-fit design
  • No LED polarity consideration

Important 100W Warning

Higher wattage means higher electrical load and heat. Never assume a 100W bulb is suitable simply because it physically fits the P20d holder.

HB3 100W Xenon White Bulbs

Argo also offers HB3 100W xenon white bulbs.

These are filament-style bulbs designed to produce a whiter-looking light than a standard warm halogen bulb.

Are HB3 Xenon White Bulbs HID?

No. “Xenon white” in this context refers to the appearance of the light. It is not the same as a true HID xenon discharge system.

HB3 6000K LED Bulbs

HB3 LED bulbs use light-emitting diodes instead of a traditional filament.

Argo's HB3 LED version produces a 6000K cool-white output.

Benefits of HB3 LED Bulbs

  • Modern cool-white appearance
  • Instant illumination
  • Lower electrical consumption than 100W 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.

Halogen vs Xenon-Effect vs LED

Feature 100W Halogen 100W Xenon White 6000K LED
Technology Filament Filament / xenon-effect LED
Colour Warm white Whiter appearance Cool white
Wattage 100W 100W Lower electrical consumption
Heat High High Managed through heat sink/fan where applicable
Argo Range Yes Yes Yes

Which HB3 Bulb Is Best?

The best choice depends on the lamp design, desired colour, available space and electrical requirements.

100W HB3 Bulbs: Heat and Electrical Load

A 100W HB3 bulb draws more current than a lower-wattage bulb and generates significantly more heat.

Potential issues from using an unsuitable high-wattage bulb include:

  • Overheated connectors
  • Damaged wiring
  • Discoloured reflectors
  • Melted plastic housings
  • Blown fuses

💡 Argo Expert Tip

Check the original bulb specification and vehicle wiring before fitting a 100W bulb. Physical fit alone does not confirm electrical suitability.

HB3 vs HB4 / 9005 vs 9006

HB3/9005 is commonly confused with HB4/9006 because the bulbs are visually similar.

However, they use different keying and specifications and should not be treated as directly interchangeable.

Feature HB3 / 9005 HB4 / 9006
Common Reference 9005 9006
Base P20d Different keyed base
Use High beam, low beam or fog where specified Low beam or fog 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 product photographs.

HB3 HID Terminology Explained

Customers sometimes search for HB3 HID bulbs or HID headlight when looking for a whiter or brighter replacement.

A true HID system uses a gas-discharge capsule and ballast. Standard HB3 halogen, xenon-effect and LED bulbs are different technologies.

Do not assume a xenon-white HB3 filament bulb is an HID conversion.

How to Identify an HB3 / 9005 Bulb

Look for:

  • HB3 marking
  • 9005 reference
  • P20d base
  • Two-pin connector
  • Twist-lock keyed plastic base

How to Replace an HB3 Bulb

1. Switch Off the Vehicle

Turn off the ignition and lighting circuit.

2. Allow the Bulb to Cool

Halogen and 100W 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

HB3/9005 bulbs normally use a twist-lock fitting.

6. Fit the Replacement

Align the P20d locating tabs correctly and secure the bulb.

7. Reconnect and Test

Check operation before refitting covers or trim.

Common Mistakes When Buying HB3 Bulbs

Confusing HB3 with HB4

HB3/9005 and HB4/9006 are similar-looking but different bulb families.

Assuming HB3 Is Always High Beam

HB3 is commonly used for high beam, but selected vehicles use it for dipped beam, low beam or fog lights.

Assuming Xenon White Means HID

Xenon-effect filament bulbs are not HID discharge bulbs.

Choosing 100W Without Checking Wiring

100W bulbs place greater load on the circuit and generate more heat.

Assuming LED Will Fit Any Housing

LED heat sinks and fans may require extra rear clearance.

Ignoring the P20d Base

Similar bulbs may use different keying, so check the base carefully.

💡 Argo Expert Tip

Before ordering, check five things: HB3/9005 reference, P20d base, lamp position, original wattage and available space.

Frequently Asked Questions

What is an HB3 bulb?

HB3 is an automotive headlight and auxiliary-lighting bulb also commonly known as 9005.

Is HB3 the same as 9005?

Yes. HB3 and 9005 are commonly used to describe the same bulb family.

What base does HB3 use?

HB3/9005 uses the P20d base.

What is HB3 used for?

HB3 can be used for high beam, main beam, dipped beam, low beam and front fog-light applications depending on the vehicle.

Is HB3 a high-beam bulb?

HB3 is commonly used for high beam/main beam, but not exclusively.

Can HB3 be used for dipped beam?

Yes, on selected vehicles where the lamp unit specifies HB3/9005.

Can HB3 be used for low beam?

Yes, where the vehicle specifies HB3/9005 for that position.

Can HB3 be used for fog lights?

Yes. Selected vehicles use HB3/9005 for front fog-light applications.

Does Argo sell HB3 halogen bulbs?

Yes. Argo offers HB3 100W halogen bulbs.

Does Argo sell HB3 xenon bulbs?

Yes. Argo offers HB3 100W xenon white bulbs.

Does Argo sell HB3 LED bulbs?

Yes. Argo offers HB3 LED bulbs in 6000K white.

What colour is 6000K HB3 LED?

6000K is a cool white colour.

Are HB3 xenon white bulbs HID?

No. Xenon white describes the appearance of a filament bulb and is not the same as a true HID system.

What is the difference between HB3 and HB4?

HB3 is commonly referenced as 9005, while HB4 is commonly 9006. They use different keyed bases and should not be treated as directly interchangeable.

Can I replace HB3 halogen with LED?

Only where the lamp, available space, electrical system and applicable road-use requirements are suitable for the LED replacement.

Are 100W HB3 bulbs safe?

They are only suitable where the lamp housing, connector and wiring can safely handle the increased electrical load and heat.

Is HB3 a 12V bulb?

HB3/9005 is commonly used in 12V passenger-vehicle lighting systems.

Can HB3 bulbs be used as headlight replacements?

Yes, where the vehicle specifies HB3/9005 in that headlight position.

Conclusion

HB3 bulbs, also known as 9005 bulbs, are widely used across headlight and auxiliary-lighting systems.

They use the P20d base and can be found in high beam, main beam, dipped beam, low beam and front fog-light applications depending on the vehicle.

Argo Automotive Lighting offers three HB3 variants: 100W halogen, 100W xenon white and 6000K white LED.

Before buying, always verify the HB3/9005 reference, P20d base, lamp position, original wattage and available space.

Explore Argo Automotive Lighting's HB3 Headlight Bulbs collection for compatible headlight and fog-light applications.

Free UK delivery on every order.

Andrew Morris

Engineering leader at a pre-IPO startup