D2S / D2R HID Xenon vs. H4 Bulb
Comparing 2 standards across 11 specifications. 11 key differences identified.
D2S and D2R Bulbs (standardized under UN ECE Regulation 99 with a P32d base) are High-Intensity Discharge (HID) automotive lamps that produce light by igniting an electric plasma arc inside a quartz glass chamber filled with Xenon gas and metal-halide salts. Operating at 35W nominal and generating an intense 3,200 lumens (~2.1× the brightness of halogen).
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
11 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standardization
|
UN ECE R99 Category D2S / D2R / US DOT Category D2S | UN ECE R37 (H4) / US DOT FMVSS 108 (HB2 / 9003) / IEC 60061-1 |
|
Base Socket Designation
|
P32d-2 (D2S for projector lenses) | P32d-3 (D2R with black ceramic mask for reflector optics) | P43t (3 large radial metal locating tabs with 3 heavy electrical blade terminals) |
|
Luminous Flux Output
|
3,200 lumens ± 15% (Color Temperature: 4150 K to 4300 K standard OEM daylight) | Low Beam: 1,000 lumens ± 15% | High Beam: 1,650 lumens ± 15% (at 13.2 V) |
|
Arc Chamber Chemistry
|
Xenon gas (provides instant initial glow) + Mercury + Metal-Halide salts (ScI₃ / NaI create daylight white plasma arc) | — |
|
Operating Power & Voltage
|
35 W continuous @ 85 V AC steady-state electronic ballast voltage (draws ~0.41 A) | — |
|
Ignition Arc Voltage
|
23,000 V to 25,000 V (23–25 kV pulse from external electronic ballast igniter creates initial spark arc) | — |
|
Average Lifespan
|
2,500 to 3,000+ hours (5x to 8x longer than halogen tungsten filaments) | — |
|
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 |