Isuzu NPR Headlight Bulb Size

The Isuzu NPR uses 9003 and H4651 bulb sizes for high beam headlights and 9003 and H4656 bulb sizes for low beam headlights. A replacement chart documents bulb size specifications across vehicle production years from 1986 to 2013.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

High Beam Headlight

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
2006-2013	9003 (Tilt Cab)	H4	Check Price
2002-2005	H4651 (Tilt Cab)	H4651	Check Price
1986-2001	H4651	H4651	Check Price

Low Beam Headlight

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
2006-2013	9003 (Tilt Cab)	H4	Check Price
2002-2005	H4656 (Tilt Cab)	H4656	Check Price
1986-2001	H4656	H4656	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Dual-filament halogen bulb with P43t base. 12V, 60W/55W.	9003	Check Price
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4651	Check Price
ANSI standard (US & Canada). 4x6-inch rectangular sealed beam unit. Not a replaceable bulb — the entire unit is replaced. 12V.	H4656	Check Price

Other Locations

Additional Notes

The Isuzu NPR uses two distinct headlight technologies across its model range. The 9003 is a dual-filament halogen bulb with a P43t base, rated at 12V with 60W on high beam and 55W on low beam. The H4651 and H4656 are 4x6-inch rectangular sealed beam units, also rated at 12V, in which the lens, reflector, and filament form a single assembly.
The 9003 bulb handles both high and low beam functions within a single unit through its dual-filament design. This is a common arrangement in halogen headlight systems where one filament serves each beam mode.
The H4651 and H4656 sealed beam units are not interchangeable with each other. The H4651 is specified for high beam use, while the H4656 is specified for low beam use. Each position on the Isuzu NPR (1986-2005 Tilt Cab, 1986-2001 non-Tilt Cab) requires its own dedicated sealed beam unit.
Because the H4651 and H4656 are sealed beam units, the entire assembly is replaced when the light fails. There is no separate replaceable bulb inside these units.
The Isuzu NPR (Tilt Cab) transitioned from sealed beam units to the 9003 halogen bulb between the 2005 and 2006 model years. After this change, a single 9003 bulb type covers both high and low beam positions, replacing the two-unit sealed beam arrangement.
All bulb types listed across the full model range, including the 9003, H4651, and H4656, conform to ANSI standards applicable in the United States and Canada.
The Tilt Cab designation appears in the specifications for both the sealed beam era (2002-2005) and the 9003 era (2006-2013), indicating that this body configuration is a consistent fitment qualifier throughout those years.
The 9003 bulb uses a P43t base, which is a bayonet-style mount with a 43mm collar. This base type is specific to the 9003 and H4 bulb family and is not compatible with the sealed beam sockets used in earlier NPR headlight housings.