Suzuki Motorcycle GSX-R1000 Turn Signal Bulb Size

Additional Notes

• The Suzuki Motorcycle GSX-R1000 turn signal specifications reference three distinct bulb types across front and rear positions: P21W, PY21W, and 12496. All three operate at 12 volts, and both P21W and PY21W are rated at 21 watts as single-filament bulbs under the ECE standard.
• P21W and PY21W share the same wattage and voltage rating but use physically different bayonet bases. P21W uses a BA15s base, while PY21W uses a BAU15s base. These two base types are not interchangeable, as the pin offset on BAU15s prevents incorrect installation in a BA15s socket and vice versa.
• A key distinction between P21W and PY21W lies in the glass envelope. PY21W is an amber-colored bulb, meaning the color is built into the glass itself rather than produced by a colored lens. P21W uses a clear envelope, relying on an external amber lens to produce the required turn signal color.
• The 12496 designation is a Philips and Osram part number for a specialty halogen bulb rated at 12 volts. Unlike P21W and PY21W, it is not classified under the ECE naming convention, and its wattage is not stated in the specifications.
• Front turn signal fitment on the GSX-R1000 shifted from PY21W (2009, 2012, 2014-2016) to P21W for the 2017-2019 model years, with 12496 specified for 2011 and 2013.
• Rear turn signal fitment follows a partially different pattern from the front. While 2017-2019 rear positions also use P21W and 2012 uses PY21W, the 2015 rear position calls for 12496 rather than the PY21W used at the front that same year, indicating front and rear positions are not always interchangeable within the same model year.
• Because P21W and PY21W differ in base type, substituting one for the other is not mechanically possible without modifying the socket. Installers sourcing replacements for any GSX-R1000 model year must confirm whether the specified type is BA15s or BAU15s before selecting a bulb.
• The 12496 part number appears across both front and rear positions in 2011, 2013, and 2014, and at the rear in 2015, making it a recurring fitment across multiple years of the GSX-R1000 rather than an isolated application.