The Mercedes-Benz CLK63 AMG front inner turn signal uses a 1157NA bulb size, front outer uses 12961, front uses P21W, and rear uses 12496 or PY21W bulb sizes. The replacement chart covers 2007 to 2008 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Mercedes-Benz CLK63 AMG uses five distinct bulb types across its turn signal positions for the 2007-2008 model years: 1157NA, 12961, P21W, 12496, and PY21W.
The 1157NA is a dual-filament bulb rated at 12V with a 21W main filament and a 5W secondary filament, housed in natural amber glass with a BAY15d bayonet base. It serves the front inner turn signal position on the CLK63 AMG for both 2007-2008.
The BAY15d base of the 1157NA features two offset pins at different heights, which physically prevents incorrect installation of single-filament bulbs into dual-filament sockets.
The P21W is a single-filament ECE-standard bulb rated at 12V and 21W, fitted with a BA15s bayonet base. It occupies the front turn signal position for 2007-2008.
Although the 1157NA and P21W share a similar wattage on their primary filaments, their bases are not interchangeable. The 1157NA uses a BAY15d base while the P21W uses a BA15s base, making the two physically incompatible.
The PY21W shares the same 12V, 21W single-filament rating as the P21W but uses a BAU15s base, which has a single offset pin. This offset prevents it from being substituted with a standard BA15s bulb such as the P21W.
The rear turn signal position on the CLK63 AMG changed between model years. The 2007 model uses a PY21W, while the 2008 model uses a 12496, indicating these two bulbs are not interchangeable between years for that position.
The 12961 is a miniature wedge-type bulb with a W2.1x9.5d base, rated at 12V and 5W. It serves the front outer turn signal for 2007-2008 and operates at a significantly lower wattage than the other turn signal bulbs in the same vehicle.
The 1157NA is classified under the ANSI standard applicable to the United States and Canada, while the P21W and PY21W follow the ECE standard used in Europe and other international markets, reflecting the CLK63 AMG's multi-market production.
The 12496 is identified by its Philips and Osram part number as a specialty halogen bulb rated at 12V, with no filament count or wattage specified in the available data for that designation.