Nissan D21 front side marker bulbs use 194 size while rear side marker bulbs use 158 size. The replacement chart covers 1986 to 1994 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 Nissan D21 front side marker uses the 194 bulb across all listed model years, spanning 1986-1994.
The 194 is an ANSI-standardized miniature wedge bulb of the T10 type, rated at 12V and 3.78W, intended for use in the US and Canadian markets.
The rear side marker on the Nissan D21 uses the 158 bulb, which is listed for the 1986-1988 model years.
The 158 is also an ANSI-standardized T10 miniature wedge bulb rated at 12V, but draws 3W rather than the 3.78W of the 194.
Both the 194 and 158 share the same T10 miniature wedge base format, which means they are physically similar in construction, though their wattage ratings differ.
Because the 194 and 158 carry different wattage ratings, 3.78W and 3W respectively, substituting one for the other may not meet the original electrical specification for each position.