Bosch 8154 Spark Plug

Bosch OE Fine Wire Double Platinum Spark Plug

Bosch 8154 is an OE Fine Wire Double Platinum spark plug built for steady ignition performance and extended service life. It uses platinum on both the center and ground electrodes to reduce gap erosion and maintain consistent firing characteristics in demanding daily-driver and performance applications.

Compatible With select Audi, Saab, Subaru, and Toyota applications, including Audi A4, Audi A4 Quattro, Audi A6, Audi A6 Quattro, Audi R8, Audi RS4, Audi RS6, Saab 9-2X, Subaru Impreza, Saab 900, and Toyota Supra fitments listed below. Bosch 8154 is a direct-fit style spark plug for vehicles that call for a double platinum design.

Key Features

• Double platinum construction with platinum on the center electrode and ground electrode
• Fine wire center electrode design for consistent spark delivery
• Resistor spark plug with 6000 resistance
• 14 mm thread diameter, 19 mm reach, and flat seat design
• Pre-gapped to .8 for OE-style service applications
• Ceramic insulator with nickel ground electrode core and copper center electrode core
• Standard J-gap ground configuration with one ground electrode
• Bosch OE Fine Wire Double Platinum line focused on OE-style fit and durability

Product Details

The Bosch OE Fine Wire Double Platinum line is built around OE spark plug technology, using platinum where it matters most to help slow electrode wear and preserve performance over time. The fine wire center electrode supports reliable ignition, while the platinum ground electrode inlay helps reduce gap growth during service. Bosch 8154 is a practical choice for drivers maintaining factory-style ignition performance in applications such as Audi A4, Audi A4 Quattro, and Subaru Impreza.

This part cross-references common OE-style double platinum applications for the same vehicle fitments.

What It Helps Address

• Hard starting caused by worn or eroded spark plug electrodes
• Rough idle from inconsistent spark output
• Misfire conditions related to plug wear or excessive gap growth
• Loss of throttle response from degraded ignition performance
• Service intervals shortened by standard plug wear in higher-demand engines

Installation Notes

Verify the vehicle’s required spark plug specification before installation, including thread diameter, reach, seat type, and heat range. Bosch 8154 uses a 14 mm thread, 19 mm reach, flat seat, and heat range 6. Check and confirm the gap against the engine’s service specification before installing. Use proper spark plug removal and torque procedures to protect the cylinder head and ignition components.

Fits 2005-2006 Audi A4 Quattro, N/A; Fits 2008 Audi A4, N/A; Fits 2006 Audi A4, N/A; Fits 2008 Audi R8, N/A; Fits 2006-2007 Audi A6, N/A; Fits 2005-2007 Audi A6 Quattro, N/A; Fits 2007 Audi RS4, N/A; Fits 2005 Saab 9-2X, N/A; Fits 2002-2005 Subaru Impreza, N/A; Fits 2003-2004 Audi RS6, N/A; Fits 1990-1998 Saab 900, N/A; Fits 1986-1992 Toyota Supra, N/A.

Quality Assurance

Bosch designs this spark plug to meet Original Equipment specifications for double platinum applications, with materials and construction selected to support durability and stable ignition performance in OE-style service.