Bosch 7446 Spark Plug

Bosch Nickel Spark Plug 7446 Overview

The Bosch 7446 is a conventional nickel-copper spark plug built for steady ignition performance and value. It uses a heavy-duty yttrium-enhanced nickel center electrode with a copper core to support longer service life than a basic copper-core plug, while meeting or exceeding original equipment specifications for nickel-copper applications.

Compatible With Mercedes-Benz models including SL600, C280, E320, S500, and 300SL applications, Bosch 7446 is a direct-fit ignition service part for a wide range of Mercedes-Benz engines from the 1990s through the early 2000s.

Key Features

• Bosch Nickel line spark plug for secondary ignition service
• Conventional nickel-copper construction with copper-core center electrode
• Yttrium-enhanced nickel center electrode for extended wear characteristics
• Standard J-gap ground electrode design with one ground electrode
• 14 mm thread diameter, 19 mm reach, and flat seat design
• Non-resistor design with removable nut terminal
• Ceramic insulator and non-projected insulator type
• Pre-gapped to .8 mm

Product Details

The Bosch Nickel product line focuses on conventional spark plug service where OE-style fit, stable ignition, and dependable value matter. Part number 7446 follows that approach with a nickel center electrode, nickel ground electrode tip, and copper core construction to support consistent spark delivery in Mercedes-Benz ignition systems. The flat seat, 16 mm hex size, and standard electrode layout make it a practical replacement for maintenance on vehicles such as the Mercedes-Benz C230, E420, S320, and SL500. This part number 7446 is also listed for additional Mercedes-Benz applications across the 1990-2002 model years.

This part cross-references no listed interchange numbers in the provided data.

Common Uses

• Restoring weak or inconsistent spark output
• Addressing rough idle caused by worn spark plugs
• Replacing plugs with excessive electrode wear or gap growth
• Correcting misfire conditions tied to aged ignition service parts
• Maintaining factory-style ignition performance on Mercedes-Benz engines

Installation Notes

Verify the 14 mm thread diameter, 19 mm reach, flat seat, and .8 mm pre-gap before installation. Confirm the engine application against the vehicle’s service information, especially on Mercedes-Benz SL600, E320, S420, and 300E models. Use proper spark plug removal and installation procedures to avoid thread damage in the cylinder head, and check ignition wire or coil condition during service.

Quality Assurance

Bosch manufactures this spark plug to meet or exceed original equipment specifications for nickel-copper core spark plug applications. The Bosch 7446 is built as a conventional service part for consistent ignition performance in compatible Mercedes-Benz vehicles.