Bosch FR78 Spark Plug

Bosch FR78 Spark Plug Overview

The Bosch FR78 is a nickel-copper spark plug built for steady ignition performance and OE-style fitment. It uses a heavy-duty nickel center electrode with a copper core and a four-ground-electrode design to support longer service life in the right applications. Bosch FR78 is a practical choice for BMW, Mini, Bentley, Rolls-Royce, and Land Rover engines that call for this plug specification.

Key Features

• Nickel center electrode with copper core for durable ignition performance
• Four ground electrodes for a multi-electrode spark design
• Resistor spark plug with 6000 ohms resistance
• Projected ceramic insulator for stable combustion chamber exposure
• 14 mm thread diameter, 19 mm reach, and flat seat design
• Pre-gapped to .9 for the specified application
• Removable nut terminal for common ignition lead configurations
• Bosch Nickel line focuses on value-oriented nickel-copper spark plug construction

Detailed Description

Bosch FR78 is engineered as a nickel-copper core spark plug that meets or exceeds original equipment specifications for nickel-copper applications. The Bosch Nickel product line emphasizes dependable ignition performance with a heavy-duty nickel center electrode, copper core construction, and multiple ground electrodes to help maintain consistent spark delivery over time. For drivers searching for a Bosch FR78 spark plug for BMW 325i, BMW 330i, or Mini Cooper service, this plug matches the technical requirements listed for the application.

Fitment includes a wide range of vehicles such as Fits 2001-2005 BMW 325i, N/A; Fits 2002-2008 Mini Cooper, N/A; and Fits 2004-2013 Rolls-Royce Phantom, N/A. It also covers additional BMW, Bentley, Land Rover, and Rolls-Royce applications across the 1992-2013 model years. This part cross-references no listed aftermarket part numbers in the provided data.

What It Helps Address

• Hard starting caused by worn spark plug electrodes
• Rough idle from inconsistent ignition output
• Misfire conditions related to aged secondary ignition components
• Reduced throttle response from degraded spark quality
• Service intervals where the original plug has reached wear limits

Installation Notes and Tips

Verify the engine calls for a 14 mm, flat-seat, 19 mm reach spark plug with the specified heat range before installation. Check the gap specification against the vehicle service information, and confirm the removable nut terminal matches the ignition lead or coil-on-plug connection used on the engine. For fitment-based searches, Bosch FR78 is commonly referenced for BMW 325Ci, BMW 530i, and BMW X5 applications, along with Mini Cooper and Rolls-Royce Phantom models listed in the fitment data.

Quality Assurance

Bosch designs this spark plug to meet or exceed OE specifications for nickel-copper core applications. The ceramic insulator, nickel electrode materials, and resistor design support consistent secondary ignition performance in the listed vehicles.