Isuzu Stylus Back Up Light Bulb Size

The Isuzu Stylus back up light bulb uses a 1073 size bulb, with P21W designation for this specific component. The replacement chart covers vehicle production years spanning 1991 to 1993.

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

Bulb Size by Year Range

Years	Bulb Size
1993	1073
1991-1992	P21W

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. Lower wattage variant of 1156. 12V, 13W.	1073
ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W.	P21W

Other Locations

Additional Notes

The 1073 and P21W bulb types share the same BA15s bayonet base, yet they originate from different standardization systems. The 1073 follows the ANSI standard used in the United States and Canada, while the P21W follows the ECE standard used in Europe and worldwide markets.
The 1993 Isuzu Stylus uses the 1073 bulb for its back up light, whereas the 1991-1992 models use the P21W.
Although both bulb types use a BA15s bayonet base, their wattage ratings differ. The 1073 operates at 12V and 13W, while the P21W operates at 12V and 21W. This difference means the two types are not directly interchangeable despite their physical base compatibility.
The 1073 is a lower wattage variant of the 1156, another ANSI-standard single-filament bulb with a BA15s base. The reduced wattage of the 1073 reflects a design choice for applications where lower light output is sufficient.
The P21W is classified as a signalling bulb under the ECE standard, a designation that indicates its intended use in functions such as reversing lights, brake lights, and turn signals rather than primary illumination.
The shift from P21W in 1991-1992 to the 1073 in 1993 reflects a change in the regional standardization applied to the Stylus back up light specification, moving from an ECE-rated bulb to an ANSI-rated one.