The Mercedes-Benz GLC300 front turn signal uses 12174NA or 12496 bulb sizes, while the rear turn signal requires 12496. The chart covers 2016 to 2020 for replacement bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz GLC300 front turn signal specifications apply exclusively to vehicles equipped with halogen capsule headlamps across the 2016-2020 model years.
Two distinct bulb types appear across the GLC300 turn signal positions: the 12174NA and the 12496, both rated at 12V.
The 12174NA is an OEM part number designating a natural amber glass bulb, meaning the amber color is produced by the glass envelope itself rather than by a coating or lens.
The 12496 carries a Philips/Osram part number and is classified as a halogen bulb intended for specialty applications.
The rear turn signal position on the GLC300 uses the 12496 bulb uniformly across all listed model years, 2016-2020.
The front turn signal position uses the 12174NA for 2016-2018 and 2020, while the 2019 model year specifies the 12496 instead.
The 2019 front turn signal specification differs from the surrounding model years, making the 12174NA and 12496 non-interchangeable without confirming the specific model year first.
Because the 12174NA is an OEM-designated part number and the 12496 is a Philips/Osram trade part number, the two identifiers originate from different cataloging systems even though both describe 12V bulbs used in the same vehicle line.