Mercedes-Benz G65 AMG front and rear turn signal bulbs use PY21W size, with front signals also identified as 12496 bulb specification. The replacement chart covers 2016 to 2018 model years with corresponding bulb size data.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
PY21W is the most frequently specified bulb across the Mercedes-Benz G65 AMG turn signal positions, appearing in five of the six total position-year combinations listed.
PY21W is an ECE-standard single-filament amber bulb rated at 12 volts and 21 watts, fitted with a BAU15s bayonet base, and is recognized across European and worldwide automotive markets.
The BAU15s bayonet base on the PY21W features an offset pin arrangement, which physically prevents substitution with standard BA15s-based bulbs that share a similar appearance.
The 2017 front turn signal position on the Mercedes-Benz G65 AMG is specified with bulb size 12496 rather than PY21W, making it the sole position across the listed years to deviate from the PY21W specification.
The 12496 designation is a Philips/Osram part number assigned to a 12-volt halogen bulb intended for specialty automotive applications.
Because the 2017 front turn signal uses a different bulb designation than the 2016 and 2018 front positions, direct interchangeability between the 2017 front bulb and those of the surrounding model years is not confirmed by the specifications.
The rear turn signal position on the G65 AMG carries a consistent PY21W specification across the 2016-2018 model years, indicating no variation in that position over the listed period.
At 21 watts, the PY21W operates at a relatively high wattage for a signal bulb, which is a factor relevant to socket heat tolerance and compatibility with load-sensitive flasher relay circuits.