Bosch 9673 OE Double Iridium Spark Plugs Pack of 4 — Fine-Wire, OE-Matched, Long-Life

BOSCH 9673 OE Fine Wire Double Iridium Spark Plugs are high-performance, OE-matched spark plugs designed to deliver reliable ignition and extended service life for modern gasoline engines.

These spark plugs combine an ultra-fine iridium center electrode with an iridium ground-electrode inlay and a laser-welded tapered ground electrode to provide consistent ignitability and durability. Pre-gapped at the factory and built to Bosch original equipment specifications, they are engineered for modern gasoline engines including Gasoline Direct Injection (GDI) systems. Corrosion-resistant nickel-plated rolled threads simplify installation and removal, eliminating the need for anti-seize compounds.

How do these plugs improve ignition compared with standard plugs?

The ultra-fine wire iridium firing pin lowers the voltage required to ignite the air-fuel mixture, improving starting and throttle response. A laser-welded tapered ground electrode produces a cleaner, more focused spark path, which helps maintain consistent performance over time.

• Ultra-fine iridium center electrode reduces required voltage by up to 24%
• Laser-welded tapered ground electrode for stable spark formation
• Iridium ground-electrode inlay increases wear resistance and longevity

Will these fit my modern gasoline or GDI engine?

Bosch OE Fine Wire Double Iridium plugs are engineered to match original equipment specifications, including spark position and geometry used in many modern gasoline and GDI engines. Always check the correct part number and gap specification for your vehicle before installation.

• OE-matched spark position for compatibility with GDI systems
• Pre-gapped at the factory to recommended OEM gap values
• Designed to meet or exceed manufacturer fit, form, and function

What makes installation and maintenance easier?

The plugs arrive factory pre-gapped and feature nickel-plated rolled threads that resist corrosion and thread galling. Because they remove easily and don’t require anti-seize during installation, you save time and reduce the risk of damaging cylinder head threads.

• Factory pre-gapped — no gap adjustment required before installation
• Nickel-plated rolled threads resist corrosion and ease removal
• No anti-seize required, keeping installation simple and clean

How long can I expect these plugs to last?

Double iridium construction and precision welding extend electrode life compared with standard nickel or single-iridium plugs. While actual lifespan depends on engine conditions and driving habits, the advanced materials and design aim to provide a notably longer service interval than conventional plugs.

• Double iridium electrodes for superior wear resistance
• Robust construction preserves gap and performance over time
• Designed to deliver long service life under normal driving conditions

Who is this for: These Bosch 9673 OE Double Iridium spark plugs are suited to owners and technicians seeking factory-quality replacement parts for modern gasoline engines, including vehicles with GDI systems. They are ideal for drivers who want improved ignitability, reliable fitment, and reduced maintenance time when replacing spark plugs.