Mitsubishi Diamante high beam and low beam headlight bulbs utilize 9003, 9005, H7, and 9006 sizes depending on production specifications. The replacement chart covers 1992 through 2004 model years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9005 bulb is the most consistently specified type across the Mitsubishi Diamante's headlight history, serving as the high beam bulb for the 1992-2003 model years. It is an ANSI-standard single-filament halogen bulb rated at 12V and 65W, fitted with a P20d base.
The 9006 bulb holds an equally dominant presence in the low beam position, covering the Mitsubishi Diamante from 1992 through 2003. It is also an ANSI-standard single-filament halogen bulb but operates at a lower wattage of 55W and uses a P22d base, distinguishing it physically from the 9005.
The 9003 is a dual-filament halogen bulb rated at 12V with a 60W high beam filament and a 55W low beam filament, using a P43t base. Its dual-filament design means a single 9003 unit serves both beam functions within one housing.
For the 2004 model year, the Mitsubishi Diamante adopted the 9003 bulb for both the high beam and one of the listed low beam positions, representing a departure from the separate 9005 and 9006 configuration used in prior years.
The 2004 low beam position also lists the H7 as an alternative fitment. The H7 follows the ECE standard rather than the ANSI standard and uses a PX26d base, which is physically incompatible with the P22d base of the 9006 or the P43t base of the 9003.
The H7 operates at 12V and 55W, matching the wattage of the 9006, but its ECE-standard PX26d base means it is not a direct plug-in substitute for any ANSI-standard bulb listed elsewhere in these specifications.
The 9005 and 9006, while similar in appearance as single-filament halogen bulbs, use different bases, P20d and P22d respectively, making them non-interchangeable despite their shared ANSI classification and 12V operating voltage.
The presence of two distinct low beam options for the 2004 model year, the 9003 and the H7, indicates that the 2004 Diamante was produced with more than one headlight assembly configuration, each requiring a different and incompatible bulb type.