BMW 325i Headlight Bulb Size

Additional Notes

• The H7 bulb is the most frequently specified halogen type across the BMW 325i headlight data, appearing in both high beam and low beam positions for the 2001-2006 model years on halogen-equipped vehicles. It is a single-filament bulb rated at 12V and 55W, built to the ECE standard with a PX26d base, and is also approved for use in the United States and Japan.
• The D2S is the predominant HID bulb type in the specifications, covering both high beam and low beam positions for the 2002-2005 model years. It operates at 85V and 35W, uses a P32d-2 base, and is designed exclusively for projector-type housings. Unlike the D1S, the D2S requires a separate external ignitor rather than an integrated one.
• The 2006 BMW 325i with HID headlamps uses the D1S rather than the D2S specified for earlier years. The D1S also operates at 85V and 35W and is designed for projector-type housings, but it carries an integral ignitor and uses a PK32d-2 base, making it physically and electrically distinct from the D2S. These two bulb types are not interchangeable.
• The 9005 and 9006 bulbs appear in the high beam and low beam positions respectively for the 1988-1995 model years (excluding 1990-1991). Both follow the ANSI standard applicable to the US and Canada. The 9005 is rated at 65W while the 9006 is rated at 55W, and their bases differ, with a P20d on the 9005 and a P22d on the 9006, meaning the two types are not interchangeable despite their similar appearance.
• The 1990-1991 model years use sealed beam units rather than replaceable bulbs. The high beam position takes the H5001, a 4-inch square sealed beam unit, while the low beam position takes the H5006, a 5.75-inch round sealed beam unit. In both cases, the entire housing assembly is replaced rather than an individual bulb.
• Vehicles equipped with HID headlamps and those equipped with halogen capsule headlamps require different bulb types for the same model year. For 2002-2005, the HID configuration uses the D2S while the halogen configuration uses the H7. Substituting one type for the other is not supported by the specifications, as the two systems differ in voltage, wattage, base type, and housing design.
• The 2001 model year presents a split fitment for the low beam position, with the H7 listed for standard halogen headlamps and the D2S listed for HID-equipped vehicles. The high beam position for 2001 lists only the H7, with no HID variant specified for that function in that year.
• All HID bulb types in the specifications, both D1S and D2S, are rated at 85V, which is substantially higher than the 12V rating of all halogen types listed. This voltage difference reflects the fundamental operating distinction between high-intensity discharge and halogen lamp technologies.