BMW M5 front side marker bulbs utilize 12961, 3357NA, or 3457NA sizes, while rear side marker bulbs require 12821 size. The replacement chart covers 1991 through 2007 production years with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The BMW M5 front side marker uses two distinct bulb families across its model years: the miniature T10 wedge type for certain years and the larger T25 wedge type for others.
The 12961 and 12821 are both Philips part numbers designating miniature T10 wedge bulbs with a W2.1x9.5d base, rated at 12V and 5W. Despite carrying different part numbers, their base type and voltage-wattage ratings are identical.
The BMW M5 (2006-2007) and (1991-1993) share the 12961 bulb for the front side marker position, indicating the same T10 form factor was specified across two separate production periods.
The 3357NA is an ANSI-standard single-filament T25 wedge bulb with natural amber glass, rated at 12V and 27W. Its natural amber coating produces the amber color output without relying on a tinted housing.
The BMW M5 front side marker for 2000, 2002, and 2003 uses the 3357NA, a single-filament bulb, while the 2001 model year specifies the 3457NA, a dual-filament variant of the same T25 form factor.
The 3457NA carries a dual-filament rating of 27W and 7W, meaning it supports two independent brightness levels within a single bulb envelope, unlike the single-filament 3357NA used in adjacent model years.
Substituting a 3357NA for a 3457NA in the 2001 front side marker position would result in a single-filament bulb replacing a dual-filament application, which may affect circuit function if both filaments are independently activated by the vehicle.
The rear side marker on the BMW M5 for 2000-2002 uses the 12821, a T10 miniature wedge bulb rated at 12V and 5W, the same base type as the 12961 used in the front position for other model years.
The W2.1x9.5d base designation shared by the 12961 and 12821 refers to a standardized wedge pin configuration, where the numerical values describe the contact width and pin spacing in millimeters.
The T25 designation on the 3357NA and 3457NA refers to the tubular bulb envelope width expressed in eighths of an inch, making the T25 physically larger than the T10 used in the miniature wedge applications elsewhere in these specifications.