# item.guide
Side-by-Side Comparison Light Bulbs & Sockets

D2S / D2R HID Xenon vs. W5W / T10 Bulb

Comparing 2 standards across 11 specifications. 11 key differences identified.

Comparing:
D2S / D2R HID Xenon
W5W / T10 Bulb

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).

View full D2S / D2R HID Xenon spec sheet →

The W5W Bulb (commonly called a T10 Wedge or 194 / 168 in North America, standardized under ECE Regulation 37 with a W2.1×9.5d base) is the universal automotive miniature capless glass bulb. Operating at 5W at 12V (generating ~50 lumens), it is the standard for front parking lights, side turn indicators, license plate lamps, and cabin interior courtesy lights.

View full W5W / T10 Bulb spec sheet →

Specification Comparison Table

11 Parameters
Parameter / Spec
Standardization
UN ECE R99 Category D2S / D2R / US DOT Category D2S UN ECE R37 Category W5W / US DOT Type 194 / 168 / IEC 60061-1
Base Socket Designation
P32d-2 (D2S for projector lenses) | P32d-3 (D2R with black ceramic mask for reflector optics) W2.1×9.5d (Capless glass wedge base: 2.1 mm thickness × 9.5 mm width)
Luminous Flux Output
3,200 lumens ± 15% (Color Temperature: 4150 K to 4300 K standard OEM daylight) 50 lumens ± 20% (at 13.5 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)
Bulb Envelope Diameter
T10 designation indicates tubular glass envelope diameter of 10.0 mm (3/8 in)
Nominal Power & Voltage
5 W @ 12V (tested at 13.5 V; draws approx. 0.40 A)
Electrical Contact Wires
Two bare molybdenum lead wires folded across opposite sides of the flattened glass wedge base
Applications
Front sidelights/eyebrow markers, side fender repeaters, license plate illumination, interior map/dome lights, trunk cargo lamps