Oldsmobile Dynamic 88 Back Up Light Bulb Size

The Oldsmobile Dynamic 88 back up light utilizes P21W and 1073 bulb sizes for the rear illumination system. Data for the specific lighting components covers the period from 1958 to 1966.

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
1962-1966	P21W
1961	1073
1960	P21W
1959	1073
1958	P21W

Bulb Specifications

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

Other Locations

Additional Notes

The Oldsmobile Dynamic 88 back up light bulb specifications span model years 1958 through 1966, covering two distinct bulb types across that period.
The P21W is the more frequently specified bulb across these years, appearing in the 1958, 1960, and 1962-1966 model years of the Dynamic 88.
The P21W is an ECE-standard single-filament signalling bulb rated at 12 volts and 21 watts, fitted with a BA15s bayonet base.
The BA15s designation refers to a single-contact bayonet base with a 15mm collar, a common base type in automotive lighting applications of that era.
The 1073 bulb is specified for the 1959 and 1961 Dynamic 88 model years.
The 1073 follows the ANSI standard used in the United States and Canada, operating at 12 volts and 13 watts, also with a BA15s bayonet base.
Although the P21W and 1073 share the same BA15s bayonet base, their wattage ratings differ significantly, at 21 watts and 13 watts respectively, which affects light output.
Because the two bulb types share a base configuration, physical fitment between them is possible, though the difference in wattage means they are not electrically equivalent substitutes.