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

H11 Bulb vs. W5W / T10 Bulb

Comparing 2 standards across 10 specifications. 10 key differences identified.

Comparing:
H11 Bulb
W5W / T10 Bulb

The H11 Bulb (standardized under UN ECE Regulation 37 with a PGJ19-2 right-angle plastic base) is the modern standard for front fog lights and projector low-beam headlights. Featuring a built-in silicone weather-sealing O-ring, an integrated 90-degree automotive locking connector, and an axial 55W filament generating 1,350 lumens.

View full H11 Bulb 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

10 Parameters
Parameter / Spec
Standardization
UN ECE R37 Category H11 / US DOT Category H11 UN ECE R37 Category W5W / US DOT Type 194 / 168 / IEC 60061-1
Base Socket Designation
PGJ19-2 (Right-angle molded plastic base with 3 asymmetrical metal locking tabs) W2.1×9.5d (Capless glass wedge base: 2.1 mm thickness × 9.5 mm width)
Nominal Power & Voltage
55 W @ 12V (tested at 13.2 V; draws 4.17 A) 5 W @ 12V (tested at 13.5 V; draws approx. 0.40 A)
Luminous Flux Output
1,350 lumens ± 10% (at 13.2 V) 50 lumens ± 20% (at 13.5 V)
Weatherproofing
Integrated orange high-temperature silicone O-ring seals directly against headlight housing barrel
Electrical Plug
Integrated female automotive connector with locking snap tab (IEC 60061-1)
Related Family (H8 / H9 / H16)
H8: 35W (PGJ19-1) | H9: 65W (PGJ19-5, 2100 lm) | H11: 55W (PGJ19-2) | H16: 19W (PGJ19-3)
Bulb Envelope Diameter
T10 designation indicates tubular glass envelope diameter of 10.0 mm (3/8 in)
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