Hyundai Elantra Turn Signal Bulb Size

Additional Notes

• The Hyundai Elantra's front turn signal uses two distinct bulb types across its production history: the PY21W for 2021-2024 models and the 2357NA for 1999-2020 models, with earlier generations using the 2357 or 1157.
• The PY21W follows the ECE standard used in Europe and worldwide markets. It is a single-filament amber bulb rated at 12V and 21W, fitted with a BAU15s bayonet base, which is not interchangeable with the BA15s or BAY15d bases found on other bulbs in these specifications.
• The 2357NA is an ANSI-standard dual-filament bulb with a BAY15d bayonet base and natural amber glass coating. It operates at 12V with a high-filament draw of 26.9W and a low-filament draw of 8W, making it the most frequently specified front turn signal bulb across the Elantra's history.
• The 2357 and 2357NA share the same BAY15d base and wattage ratings, but the 2357NA carries a factory-applied natural amber glass coating rather than a clear envelope. The two are physically interchangeable at the socket level, though the clear 2357 lacks the amber tint built into the NA variant.
• The 1157, specified for the 1992 Hyundai Elantra front turn signal, also uses a BAY15d base but draws only 21W on its high filament compared to the 26.9W of the 2357 and 2357NA. Despite sharing the same base type, substituting a 2357 for a 1157 results in a higher wattage draw.
• The rear turn signal on the 2023-2024 Elantra uses the 921, a wedge-base T15 bulb rated at 12V and 16W. This bulb type uses no bayonet base at all, making it physically incompatible with the BA15s-based 1156 and 1156NA bulbs specified for earlier model years.
• The 1156NA, specified for the Elantra's rear turn signal across multiple model years, is a single-filament bulb with a BA15s bayonet base and natural amber glass. It shares its base type and 12V/21W rating with the clear 1156, but the amber coating serves to produce a colored output without relying on a tinted lens.
• The BA15s base of the 1156 and 1156NA is a single-contact bayonet fitting, while the BAY15d base of the 2357, 2357NA, and 1157 is a dual-contact offset-pin bayonet. These two base types are not interchangeable despite their similar physical appearance.