Oldsmobile Delmont 88 Back Up Light Bulb Size

The Oldsmobile Delmont 88 back up light requires bulb size 1156 or P21W depending on the specific version of the component. Data for the lighting equipment covers the period from 1967 through 1968.

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
1967-1968	1156

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156

Other Locations

Additional Notes

The 1156 is the sole bulb type listed for the Oldsmobile Delmont 88 back up light across both model years covered in the specifications, spanning 1967-1968.
The 1156 operates on a 12-volt electrical system and draws 21 watts, placing it in the range typical for single-function automotive lighting such as back up lamps.
The 1156 uses a BA15s bayonet base, which is a single-contact bayonet fitting. The "s" designation indicates a single pin offset, distinguishing it from the dual-contact BA15d variant and making the two non-interchangeable.
As a single-filament bulb, the 1156 serves one lighting function only, which aligns with its application in a dedicated back up light circuit rather than a combined stop/tail position.
The 1156 conforms to ANSI standards and carries recognition in both the United States and Canada, reflecting a standardized specification shared across North American automotive markets of that era.