Oldsmobile Jetstar 88 front turn signal bulbs use 1157NA or 1157 size, while rear turn signal bulbs require 1157 size. The replacement chart covers 1964 through 1966 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 1157 bulb is the most widely used type across the Oldsmobile Jetstar 88 turn signal specifications, appearing in both the front and rear positions for 1964-1965 and in the rear position for 1966.
The 1157 is a dual-filament bulb rated at 12V with a 21W high-filament and a 5W low-filament, which allows it to serve both turn signal and parking light functions within a single housing.
Both the 1157 and 1157NA share the BAY15d bayonet base, a two-pin offset base design that physically distinguishes it from single-pin bayonet types and prevents incorrect installation.
The 1157NA differs from the standard 1157 solely in its natural amber glass envelope, which produces an amber output without relying on an amber lens.
The Oldsmobile Jetstar 88 (1966) uses the 1157NA in the front turn signal position, making it the only model year in these specifications to call for the amber-glass variant at that location.
Because the 1157 and 1157NA share identical base types and electrical ratings, the physical fitment is the same, though substituting one for the other may affect the color output depending on the lens color of the housing.