BMW 528i Headlight Bulb Size

Additional Notes

• The D1S bulb is the most frequently specified type across the BMW 528i headlight data, appearing in both high beam and low beam positions for the 2008-2016 model years. It is an HID (xenon) discharge bulb operating at 85V and 35W, built to ECE standards for worldwide use. Its PK32d-2 base includes an integral ignitor, and it is designed exclusively for projector-type housings.
• The D2S also operates at 85V and 35W under ECE standards but differs from the D1S in one critical respect: it requires an external ignitor rather than a built-in one. On the BMW 528i, the D2S appears only in the low beam position for the 1997-2000 model years on vehicles equipped with HID headlamps. The two bulb types are not interchangeable despite sharing the same wattage and voltage rating.
• The H7 is a single-filament halogen bulb rated at 12V and 55W with a PX26d base, built to ECE standards but also approved for use in the US and Japan. On the 528i, it serves as the halogen alternative to HID in both high beam and low beam positions for 2008-2010, and as the sole low beam option in halogen-equipped vehicles from 1997-2000.
• For the 2008-2010 BMW 528i, both the D1S and H7 are listed for the same beam positions, reflecting two distinct headlamp system configurations available in those years. The HID variant uses the D1S, while the halogen capsule variant uses the H7. These are separate fitments tied to the installed headlamp assembly type and are not interchangeable with each other.
• The 9005 is an ANSI-standard single-filament halogen bulb rated at 12V and 65W with a P20d base. It appears only in the high beam position for the 1997-2000 528i. At 65W, it draws more power than the H7's 55W, and the two bulbs use different bases, making them incompatible with each other's sockets.
• The H5001 is a 4-inch square sealed beam unit specified for the high beam position on the 1979-1981 528i. Unlike discrete replaceable bulbs, the entire sealed beam assembly is the serviceable unit. It operates at 12V and conforms to ANSI standards applicable in the US and Canada.
• The H5006 is a 5.75-inch round sealed beam unit specified for the low beam position on the same 1979-1981 model years. Like the H5001, it is a complete sealed assembly rather than a replaceable bulb, and it also operates at 12V under ANSI standards. The H5001 and H5006 are physically distinct units and serve different beam functions.
• Across the full span of the 528i specifications, three distinct lighting technologies are represented: sealed beam assemblies in the earliest years, halogen capsule bulbs in mid-range years, and HID xenon discharge bulbs from the late 1990s onward. Each technology uses incompatible bases and operating voltages, meaning no substitution is possible across technology types without a corresponding change in the headlamp housing.