Mercedes-Benz GLC63 AMG front turn signal bulbs use 12174NA or 12496 size, while rear turn signal bulbs use 12496 size. The chart covers 2018 to 2020 replacement bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 12496 is the most frequently referenced bulb across these specifications, appearing in the rear turn signal position for all three model years (2018-2020) as well as the front turn signal position for the 2019 model year.
The 12496 carries a Philips/Osram part number and is classified as a halogen bulb intended for specialty applications, operating at 12V.
The 12174NA is an OEM part number designating a natural amber glass bulb that operates at 12V. The "NA" suffix in its designation indicates the natural amber glass construction, which produces an amber output without the use of a painted or coated envelope.
The 12174NA is specified for the front turn signal of the Mercedes-Benz GLC63 AMG in the 2018 and 2020 model years, both under the halogen capsule headlamp condition.
The 2019 front turn signal position departs from the 12174NA used in 2018 and 2020, instead calling for the 12496, making the three model years non-uniform in their front turn signal fitment despite sharing the same halogen capsule headlamp condition.
All front turn signal entries across 2018-2020 carry the qualifier "With Halogen Capsule Headlamps," indicating that these bulb sizes apply specifically to vehicles equipped with that headlamp configuration.
The 12174NA and 12496 are both 12V bulbs, but they originate from different part numbering systems. Substituting one for the other without confirming physical and electrical compatibility would be inconsistent with the year-specific fitment data provided.
The rear turn signal position uses the 12496 uniformly across 2018-2020, carrying no conditional qualifier, in contrast to the front turn signal entries which are conditioned on headlamp type.