Kia Forte Turn Signal Bulb Size

Additional Notes

• The 2357NA is the most frequently specified front turn signal bulb across the Kia Forte lineup, appearing in model years 2010-2018. It is an ANSI-standard dual-filament bulb with a BAY15d bayonet base, rated at 12V and 26.9W on its high-filament circuit and 8W on its low-filament circuit, with natural amber glass to produce the required amber signal color.
• The PY21W is an ECE-standard single-filament amber bulb with a BAU15s bayonet base, rated at 12V and 21W. It serves as both the front and rear turn signal bulb on the 2021 and 2024 Forte, and as the rear turn signal on the 2023 model.
• The BAU15s base of the PY21W is offset, meaning it is not interchangeable with the BA15s or BAY15d bases found on other bulbs in these specifications, even though the physical size of the bulb may appear similar.
• The 2357NA and the 1034NA share the same BAY15d bayonet base, but they carry different wattage ratings. The 2357NA is rated at 26.9W/8W while the 1034NA is rated at 21W/5W, which means the two are not direct substitutes despite their physical base compatibility.
• The 1034NA, specified for the rear turn signal on the Kia Forte from 2010-2013, is described as a variant of the 1157 bulb. It uses natural amber glass rather than a clear envelope, which is the primary distinction from a standard 1157.
• The 1156NA, used for the rear turn signal on the 2014-2018 Forte, is a single-filament bulb with a BA15s base, rated at 12V and 21W. The transition from the dual-filament 1034NA to the single-filament 1156NA between the 2013 and 2014 model years reflects a change in rear lamp circuit design.
• The 12961 is a Philips part number designating a miniature wedge bulb of the T10 form factor with a W2.1x9.5d base, rated at 12V and 5W. At 5W, it operates at a significantly lower wattage than every other turn signal bulb in these specifications, which is atypical for a primary turn signal application.
• The 12961 wedge base is physically incompatible with the bayonet-style bases used by all other bulbs in these specifications. A socket designed for a BAY15d, BA15s, or BAU15s bulb cannot accept a W2.1x9.5d wedge bulb without an adapter.
• The 2022 Kia Forte uses the 12961 for both its front and rear turn signals, making it the only model year in these specifications to use a wedge-base bulb in both turn signal positions.
• Across the front turn signal positions, four distinct bulb types are specified over the 2010-2024 range, indicating that direct cross-year substitution is not reliable without confirming the exact model year of the vehicle.