Bosch 9664 Spark Plug

Bosch OE Fine Wire Double Iridium Spark Plug 9664

Bosch OE Fine Wire Double Iridium spark plug 9664 is built for direct OE-style ignition performance with a fine-wire iridium center electrode and a laser-welded tapered ground electrode. It is engineered for strong ignitability, stable combustion, and long service life in applications such as Dodge Ram 1500, Jeep Grand Cherokee, and Dodge Durango.

Key Features

• Fine-wire iridium center electrode for consistent spark delivery
• Laser-welded tapered ground electrode for improved ignitability
• Double iridium construction for durability in high-demand ignition systems
• Preset 1.1 mm gap; do not gap before installation
• Resistor design with 6000 ohm resistance
• Flat seat, 14 mm thread diameter, 19 mm reach, 16 mm hex
• Ceramic insulator with non-projected tip design

Product Details

Bosch OE Fine Wire Double Iridium 9664 uses an iridium-alloy center electrode firing pin and a laser-welded ground electrode with iridium alloy inlay to maintain spark quality over extended service intervals. The tapered ground electrode shape supports efficient flame initiation, while the preset gap helps preserve OE calibration. This spark plug is a direct choice for 2000-2009 Dodge Durango, 2002-2009 Dodge Ram 1500, 1999-2007 Jeep Grand Cherokee, and related Chrysler Aspen, Dodge Dakota, Jeep Commander, and Mitsubishi Raider applications listed in the fitment data. Bosch OE Fine Wire Double Iridium is the product line for drivers and technicians looking for OE-style ignition parts with fine-wire electrode construction and long-life materials. Part number 9664 is also referenced as Bosch 9664 in catalog searches.

Common Issues This Part Addresses

• Hard starting caused by worn or eroded spark plug electrodes
• Misfire conditions from weak or inconsistent spark output
• Rough idle and hesitation under load
• Reduced fuel efficiency from incomplete combustion
• Service intervals shortened by standard plug wear

Installation Notes

• Compatible With 2007-2009 Chrysler Aspen, N/A; do not gap, gap is preset.
• Compatible With 2002-2009 Dodge Ram 1500, N/A; do not gap, gap is preset.
• Compatible With 2006-2009 Jeep Commander, N/A; do not gap, gap is preset.
• Compatible With 2000-2008 Dodge Durango, N/A; do not gap, gap is preset.
• Compatible With 2000-2007 Dodge Dakota, N/A; do not gap, gap is preset.
• Compatible With 1999-2007 Jeep Grand Cherokee, N/A; do not gap, gap is preset.
• Compatible With 2006-2007 Mitsubishi Raider, N/A; do not gap, gap is preset.
• Compatible With 2003-2004 Jeep Grand Cherokee, N/A; do not gap, gap is preset.
• Verify the engine application and original plug specification before installation.

Quality Assurance

Bosch designs this spark plug with OE-style materials and laser-welded electrode construction to support consistent ignition performance and long service life. Part number 9664 is built to match the listed factory applications and preset gap requirements for the vehicles shown.