The BMW 740iL brake component utilizes P21/5W and P21W bulb sizes according to the provided technical specifications. Available information covers the production range from 1993 through 2001.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The BMW 740iL brake bulb specifications cover model years 1993-2001 across three lighting positions: the standard brake light, the Center High Mount Stop Light, and the Outer Brake light.
Two bulb types are present across these specifications: the P21/5W and the P21W, both of which are ECE-standard bulbs rated at 12 volts and recognized for use in European and worldwide automotive applications.
The P21W is a single-filament signalling bulb operating at 21 watts and fitted with a BA15s bayonet base, which has a single contact pin at its base.
The P21/5W is a dual-filament signalling bulb rated at 21 watts and 5 watts respectively, fitted with a BAY15d bayonet base, which uses two offset pins to prevent incorrect installation of the filament orientation.
Because the P21W and P21/5W use different bayonet bases, BA15s and BAY15d respectively, the two bulb types are not interchangeable despite sharing a similar physical profile and 21-watt primary filament rating.
The standard brake light position on the BMW 740iL transitioned from P21W for model years 1993-1998 to P21/5W for model years 1999-2001, reflecting a change in base type and filament configuration between those production periods.
The Center High Mount Stop Light uses the P21W single-filament bulb consistently across all model years from 1993-2001.
The Outer Brake light position uses the P21/5W dual-filament bulb for all listed model years, which span 1995-2001.
For model years 1999-2001, the standard brake light and the Outer Brake light both specify the P21/5W, while the Center High Mount Stop Light retains the P21W, meaning two distinct bulb types are required across the three brake light positions during those years.
For model years 1993-1998, the standard brake light specifies the P21W, which shares the same bulb type as the Center High Mount Stop Light, though the Outer Brake light for 1995-1998 specifies the P21/5W with its differing BAY15d base.