The Mercedes-Benz SL63 AMG front turn signal requires a PY24WNA bulb size, while rear turn signals use either 12496 or PY21W bulb sizes. The replacement chart covers 2009 to 2012 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 PY24WNA is the most frequently specified bulb across these turn signal positions, appearing in the front turn signal slot for the Mercedes-Benz SL63 AMG across all three model years listed.
PY24WNA is an ANSI-standard amber bulb rated at 12V and 24W, using a PGU20-4 base. It is the North American market equivalent of the ECE-standard PY24W, with the "NA" suffix denoting its regional designation for the United States and Canada.
The PGU20-4 base on the PY24WNA is a wedge-type connector specific to this bulb family. It is not interchangeable with bayonet-style bases used on other amber signal bulbs.
The PY21W is an ECE-standard single-filament amber bulb rated at 12V and 21W, using a BAU15s bayonet base. The BAU15s base features offset pins to prevent incorrect installation of non-amber bulbs in amber-designated sockets.
The rear turn signal on the 2011-2009 SL63 AMG uses the PY21W, while the 2012 model year shifts to the 12496 part number for the same position, indicating a specification change between those years.
The 12496 is a Philips/Osram proprietary part number for a 12V halogen bulb intended for specialty applications. Because it is identified by a manufacturer part number rather than a universal ECE or ANSI designation, direct substitution with generic equivalents requires cross-referencing against that specific part number.
The front and rear turn signal positions on the SL63 AMG do not share a common bulb type in any of the listed model years, meaning the two positions require separate bulb selections and are not interchangeable with each other.
The PY24WNA and PY21W differ in both wattage and base type, making them physically and electrically incompatible despite both being amber single-filament signal bulbs. The PY24WNA draws 24W against the PY21W's 21W rating.