Mercedes-Benz SLC300 high beam headlight bulbs use D1S, H15, or H7 sizes, while low beam headlight bulbs use D1S or H7 sizes. The replacement bulb chart covers 2017 to 2020 production years.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The D1S bulb is the most frequently specified type across these headlight entries, appearing in both high beam and low beam positions for the 2017-2018 model years and in the HID-equipped variant of the 2020 model year. D1S is a high-intensity discharge bulb with an integrated igniter, operating at approximately 85 volts after an initial high-voltage arc strike, and it produces light through a xenon gas discharge rather than a heated filament.
The H7 bulb appears in multiple positions across the specifications. It is a halogen single-filament bulb rated at 55 watts and 12 volts, commonly used in both high beam and low beam applications. In the Mercedes-Benz SLC300, the H7 serves as the low beam bulb for the 2019 model year and as the low beam for the non-HID 2020 variant.
The H15 bulb is specified exclusively for the high beam position on the 2020 SLC300 without HID headlamps. The H15 is a dual-filament halogen bulb with a high-wattage filament for the main beam and a lower-wattage filament typically used for daytime running light functions, making it functionally distinct from single-filament types like the H7.
The 2019 SLC300 is specified with H7 bulbs for both the high beam and low beam positions, making it the only model year in these specifications where neither position calls for a D1S or any HID-type bulb.
The 2020 SLC300 carries two separate bulb specifications for both the high beam and low beam positions, contingent on whether the vehicle is equipped with HID headlamps. Substituting a D1S for an H7 or H15, or vice versa, is not possible without significant electrical and housing modifications, as HID and halogen systems operate on fundamentally different electrical architectures.
The D1S bulb is not interchangeable with other common HID types such as D2S or D3S, despite superficial similarities. The D1S has an integrated igniter built into the bulb base, whereas D2S requires a separate external igniter. Installing an incompatible HID type risks improper arc positioning and potential housing damage.