The Mercedes-Benz C63 AMG S uses a 12174NA bulb size for front turn signals and 12496 or PY21W bulb sizes for rear turn signals. The replacement chart covers 2015 to 2019 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 Mercedes-Benz C63 AMG S uses the 12174NA bulb for the front turn signal across all listed model years, 2015-2019, when equipped with halogen capsule headlamps.
The 12174NA is an OEM-designated part number featuring natural amber glass construction and operates at 12V.
The natural amber glass of the 12174NA produces its amber signal color through the glass itself rather than through a colored lens or coating on the bulb envelope.
The rear turn signal of the C63 AMG S alternates between two distinct bulb sizes depending on the model year, with 12496 fitted in 2015, 2017, and 2019, and PY21W fitted in 2016 and 2018.
The PY21W follows the ECE (Economic Commission for Europe) standard and uses a BAU15s bayonet base, which is an offset single-pin base. This base is not interchangeable with the more common BA15s base used on non-amber-specific bulbs.
The PY21W operates at 12V with a 21W output and is a single-filament bulb, meaning it serves only one lighting function per unit.
The 12496 carries a Philips/Osram part number and is classified as a halogen bulb for specialty applications, also operating at 12V.
Because the rear turn signal position alternates between the 12496 and PY21W across consecutive model years, these two bulb types are not interchangeable with one another despite occupying the same position on the vehicle.