Bosch 9687 Spark Plug

Bosch OE Fine Wire Double Iridium Spark Plug

Bosch 9687 is an OE Fine Wire Double Iridium spark plug built for precise ignition performance and extended service life. It uses an ultra-fine wire center electrode, a laser-welded ground electrode, and iridium-based electrode materials to support consistent spark delivery in demanding 4-cycle engines.

The Bosch OE Fine Wire Double Iridium line focuses on OE-style fit and durable ignition performance. For drivers servicing a Toyota Prius C, Mitsubishi Endeavor, Mitsubishi Galant, or Mitsubishi Eclipse, Bosch 9687 provides a direct spark plug option engineered around fine-wire ignitability and long-term electrode stability.

Key Features

• Fine wire center electrode with iridium tip for efficient spark initiation
• Laser-welded ground electrode with iridium-platinum tip material
• J-gap ground configuration with a flat seat design
• Resistor spark plug design for modern ignition systems
• 14 mm thread diameter, 19 mm reach, and 16 mm hex size
• Manufacturer heat range 7 for OE-style thermal control
• Ceramic insulator with projected insulator type
• Pre-gapped to .8 for specified applications

Product Details

Bosch 9687 is a double iridium spark plug designed for 4-cycle automotive engines that call for a 14 mm, flat-seat plug with a 19 mm reach. The copper core center electrode, nickel ground electrode core, and iridium-alloy firing surfaces are selected to support stable combustion, reliable cold starts, and consistent performance over extended service intervals. This part number is commonly searched as Bosch 9687 spark plug and Bosch OE Fine Wire Double Iridium 9687.

Fitment coverage includes 2012-2019 Toyota Prius C, 2004-2008 Mitsubishi Endeavor, 2010-2011 Mitsubishi Endeavor, 2004-2007 Mitsubishi Galant, 2009 Mitsubishi Galant, and 2004-2005 Mitsubishi Eclipse. This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.

What It Helps Address

• Hard starting caused by worn spark plug electrodes
• Rough idle from inconsistent ignition firing
• Misfire conditions related to plug wear or gap drift
• Reduced throttle response from weak spark delivery
• Maintenance intervals that require OE-style spark plug replacement

Installation Notes and Tips

Verify engine application, thread diameter, reach, seat type, and heat range before installation. Bosch 9687 is a flat-seat, resistor-style spark plug with a pre-gap specification of .8, so confirm the engine’s required gap and torque procedure before service. Inspect ignition coils, boots, and plug wells during replacement to help ensure consistent results. Use the vehicle service manual for final installation specifications.

Quality Assurance

Bosch OE Fine Wire Double Iridium plugs are built around laser-welded electrode construction and iridium-based firing surfaces to support durable ignition performance in OE-type applications. Bosch 9687 is engineered for the listed Toyota Prius C and Mitsubishi applications with attention to fit, thermal range, and ignition consistency.