The Isuzu Oasis front turn signal uses a 2057 bulb size while rear turn signals require either 7440NA or 7440 bulb sizes. The replacement chart covers 1996 through 1999 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Isuzu Oasis uses two distinct bulb types across its front and rear turn signal positions for the 1996-1999 model years: the 2057 at the front and either the 7440 or 7440NA at the rear.
The 2057 is a dual-filament bulb with a BAY15d bayonet base, rated at 12V with filaments drawing 26.9W and 8W respectively, and it conforms to ANSI standards applicable in the US and Canada.
The 2057 is noted as a brighter variant of the 1157, meaning it shares the same BAY15d base type but produces higher output on its primary filament.
The front turn signal position on the Isuzu Oasis uses the 2057 bulb consistently across all four model years, 1996-1999.
The rear turn signal position uses the 7440 for the 1996-1997 model years and transitions to the 7440NA for 1998-1999.
Both the 7440 and 7440NA are single-filament T20 wedge bulbs rated at 12V and 21W, conforming to the same ANSI standard.
The 7440NA variant differs from the standard 7440 in that it features natural amber glass, which produces an amber-colored output without the use of an amber-tinted housing or lens.
Because the 7440 and 7440NA share the same T20 wedge base and electrical ratings, they are physically interchangeable, though substituting a 7440 for a 7440NA would affect the amber color output if the housing itself is clear.
The 2057 and 7440 series bulbs are not interchangeable with each other, as the 2057 uses a BAY15d bayonet base while the 7440 series uses a wedge base, and the two also differ in filament count.