The Buick Lucerne front turn signal requires a 4157NA or 5702AK bulb size, while the rear turn signal uses a 3057 bulb size. The replacement chart covers vehicle production spanning 2006 to 2011 with corresponding bulb specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Buick Lucerne rear turn signal position uses the 3057 bulb across all model years covered in the specifications, from 2006-2011.
The 3057 is an ANSI-standardized dual-filament wedge bulb in the T25 form factor, rated at 12V with a 27W high filament and 7W low filament.
The front turn signal position alternates between two bulb types across the Lucerne's model years, with the 4157NA fitted in 2006, 2008-2009, and 2011, while the 5702AK is fitted in 2007 and 2010.
The 4157NA is an ANSI-standardized dual-filament T25 wedge bulb with natural amber glass, rated at 12V, 27W/7W. The amber color is produced by the glass itself rather than a surface coating.
The 5702AK is a Sylvania-specific part number for a variant of the ANSI 3157 bulb. It shares the same T25 form factor and 12V, 27W/7W electrical ratings as the 4157NA, but achieves its amber output through a surface coating rather than tinted glass.
Because the 5702AK is a manufacturer-specific designation rather than an ANSI standard number, sourcing an equivalent from other brands requires cross-referencing it to its base ANSI type, the 3157, with an amber coating applied.
The 4157NA and 5702AK share the same T25 physical form factor and identical wattage ratings, but the difference in amber treatment means they are not straightforward substitutes where regulations or OEM specifications distinguish between coated and natural amber sources.
All three bulb types in these specifications, the 4157NA, 5702AK, and 3057, are dual-filament bulbs. In turn signal applications, the higher-wattage filament (27W) typically handles the flashing function, while the lower-wattage filament (7W) serves a secondary role such as parking or running light duty.