BMW Motorcycle K1200GT front turn signal bulbs use H21W or PY21W sizes, while rear turn signal bulbs use P21W, 12496, or PY21W sizes. The replacement chart covers 2003 to 2008 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The BMW Motorcycle K1200GT front turn signal uses the H21W bulb for model years 2005-2008. This is an ECE-standard single-filament signalling bulb rated at 12V and 21W, fitted with a BAY9s base.
The front turn signal position on the K1200GT shifted from the PY21W bulb in 2003-2004 to the H21W bulb from 2005 onward. Although both are rated at 12V and 21W, these two bulbs use different base types and are not interchangeable.
The PY21W is an ECE-standard amber single-filament bulb with a BAU15s bayonet base, rated at 12V and 21W. Its amber glass produces the required turn signal color without relying on the lamp housing for tinting.
The H21W uses a BAY9s base, which is physically distinct from the BAU15s base of the PY21W. The offset pin arrangement on each base type is specific to its socket, preventing incorrect installation between the two.
The rear turn signal on the K1200GT uses the P21W bulb for model years 2005-2008. This is an ECE-standard single-filament signalling bulb with a BA15s bayonet base, rated at 12V and 21W.
The P21W differs from the PY21W primarily in its base type and glass color. The P21W uses a BA15s base with a clear or white glass envelope, while the PY21W uses a BAU15s base with an amber envelope. These are not interchangeable.
The 2004 rear turn signal position specifies the 12496, a Philips/Osram part number designating a halogen bulb for specialty applications rated at 12V. This designation differs from the ECE-standard nomenclature used across all other positions in these specifications.
All three ECE bulb types present across these specifications, H21W, PY21W, and P21W, share a 21W power rating at 12V, which is the standard wattage for automotive turn signal applications under ECE regulations.