9005 Bulb (HB3) vs. H4 Bulb
Comparing 2 standards across 10 specifications. 10 key differences identified.
The 9005 Bulb (designated as HB3 under ECE Regulation 37 with a P20d right-angle base) is the high-output single-filament halogen standard designed specifically for dedicated automotive high-beam headlights. Operating at 65W nominal at 12V, generating a powerful 1,700 lumens with an unpainted clear quartz bulb tip for maximum forward optical throw.
The H4 Bulb (marketed as 9003 or HB2 in North America under DOT regulations, standardized with a P43t 3-prong base) is the legendary dual-filament automotive headlight bulb. Containing both a 55W low-beam filament (equipped with an internal stamped metal anti-glare shield cup) and a 60W high-beam filament inside a single halogen quartz glass capsule.
Specification Comparison Table
10 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standardization
|
UN ECE R37 (HB3) / US DOT FMVSS 108 (9005) / IEC 60061-1 | UN ECE R37 (H4) / US DOT FMVSS 108 (HB2 / 9003) / IEC 60061-1 |
|
Base Socket Designation
|
P20d (90° right-angle molded plastic base with 3-tab bayonet twist lock) | P43t (3 large radial metal locating tabs with 3 heavy electrical blade terminals) |
|
Luminous Flux Output
|
1,700 lumens ± 12% (high photometric output for long-distance night penetration) | Low Beam: 1,000 lumens ± 15% | High Beam: 1,650 lumens ± 15% (at 13.2 V) |
|
Nominal Power & Voltage
|
65 W @ 12V (tested at 13.2V; draws ~4.92 A) | — |
|
Quartz Bulb Tip
|
Clear glass tip (no black top coating; allows 100% of forward light to escape into high-beam reflectors) | — |
|
Low-Beam Sibling (9006 / HB4)
|
9006 / HB4 is the 55W / 1,000 lm low-beam counterpart (P22d base with a black-coated top tip) | — |
|
Filament Architecture
|
— | Dual tungsten filaments: Low Beam (55W) + High Beam (60W) |
|
Internal Anti-Glare Shield
|
— | Stamped nickel cup positioned under the low-beam filament blocks downward light, creating a crisp horizontal beam cutoff |
|
Electrical Connector
|
— | 3-prong female socket (Ground, Low Beam 12V+, High Beam 12V+) |
|
Application Domain
|
— | Standard in motorcycles (single headlight unit), compact hatchbacks, classic 7-inch round sealed-beam replacements |