INFINITI Q45 Headlight Bulb Size

Additional Notes

• The 9005 bulb is an ANSI-standard single-filament halogen type operating at 12V and 65W with a P20d base. It serves as the high beam bulb in the Infiniti Q45 for the 1990-1996 model years and again for 2005-2006, making it the most frequently specified high beam bulb across the Q45's production span.
• The H1 is an ECE-standard single-filament halogen bulb with a P14.5s base, rated at 12V and 55W. It holds approval in the US and Japan in addition to European and worldwide markets. On the Q45, it appears as a high beam fitment for 2002-2004 and as an alternative high beam option for 1999-2001.
• The 9003 is an ANSI-standard dual-filament halogen bulb with a P43t base, rated at 12V with a 60W high filament and a 55W low filament. Its dual-filament design means a single bulb can serve both beam functions within one housing. On the Q45, it is listed for both high beam and low beam positions across the 1996-2001 range, and as a low beam fitment for 1993-1995 late-model and 1997-1998 units.
• The D2S and D2R are both HID (xenon) discharge bulbs operating at 85V and 35W, each requiring an external ignitor to initiate the arc. The D2S carries a P32d-2 base and is designed for projector-type housings, while the D2R carries a P32d-3 base and is intended for reflector-type housings. These two bulbs are not interchangeable despite their shared electrical ratings, as the internal shield geometry differs to suit each housing type.
• D2S fitment applies to the Q45 low beam for 2002-2006, while D2R fitment applies for 1999-2001. The base codes P32d-2 and P32d-3 are physically distinct, so a D2S cannot be substituted for a D2R or vice versa without a corresponding change in the headlight housing type.
• The 9006 is an ANSI-standard single-filament halogen bulb with a P22d base, rated at 12V and 55W. It is specified as the low beam bulb for the Q45 from 1990-1992 and for the early-model 1993 unit. The P22d base is not shared with the 9005 or 9003, so these bulbs are not interchangeable despite similar voltage and wattage ratings.
• The 1993 Q45 low beam position carries a production-split fitment: early-model units use the 9006, while late-model units use the 9003. This distinction reflects a mid-year housing change and means the correct bulb type depends on the specific production variant rather than the model year alone.
• For the 1999-2001 Q45, both the 9003 and either D2R (low beam) or H1 (high beam) are listed simultaneously, indicating that two distinct headlight system configurations were available in those years. The 9003, being a dual-filament bulb, would serve both beams in a single-bulb halogen system, while the H1 and D2R pairings correspond to a separate-bulb configuration with HID low beams.