Mercedes-Benz S420 Headlight Bulb Size

Additional Notes

• The H1 bulb is a single-filament halogen type operating at 12V and 55W, built to the ECE standard and approved for use in the US and Japan. It fits a P14.5s base and serves exclusively as the high beam bulb in the Mercedes-Benz S420 for model years 1995-1999.
• The 9003 bulb is a dual-filament halogen type with a P43t base, rated at 12V and 60W/55W under the ANSI standard used in the US and Canada. In the 1994 S420, it handles both the high beam and low beam functions within a single bulb unit, making it the only year where one bulb type covers both roles.
• The H7 bulb is a single-filament halogen type rated at 12V and 55W, built to the ECE standard and also approved in the US and Japan. It fits a PX26d base and is used as the low beam bulb across model years 1995-1999, though its presence in 1997-1999 depends on whether the vehicle is equipped with halogen capsule headlamps rather than HID headlamps.
• The D2R is an HID (xenon) discharge bulb rated at 85V and 35W, built to the ECE standard. It uses a P32d-3 base and is designed specifically for reflector-type housings. It requires an external ignitor to operate, which distinguishes it from the halogen types in these specifications.
• For model years 1997-1999, the S420 low beam position accepts either an H7 or a D2R bulb depending on the headlamp system installed. These two bulb types are not interchangeable, as they differ in base type, voltage, operating technology, and housing compatibility.
• The H1 and H7 bulbs share the same wattage and voltage ratings but use different base types, P14.5s and PX26d respectively, meaning they are not physically interchangeable despite their similar electrical characteristics.
• The 9003 bulb used in the 1994 model year operates under the ANSI standard, while the H1, H7, and D2R bulbs used in 1995-1999 all fall under the ECE standard, reflecting a shift in the headlamp specification between those model years.