Denso 4085 Spark Plug

Overview of Denso U-Groove Conventional Spark Plug 4085

The Denso U-Groove Conventional spark plug 4085 is engineered for reliable ignition performance in BMW M3, M5, and M6 models. Designed with a U-groove ground electrode tip, this spark plug supports efficient combustion and consistent engine operation.

• U-groove ground electrode tip design for improved spark exposure
• Standard ground configuration with a single ground electrode
• Nickel ground electrode core and tip for durability
• Copper center electrode core with nickel tip for optimal conductivity
• Pre-gap size of 0.9 mm for precise spark gap
• Flat seat type ensuring proper sealing
• Thread diameter of 12.00 mm and reach of 19.00 mm
• Hex size of 18.0 mm for standard installation tools
• Manufacturer heat range of 22 suitable for specified BMW models

Details on the U-Groove Conventional Product Line

The U-Groove Conventional line by Denso focuses on spark plugs featuring a unique U-groove ground electrode tip design. This design enhances spark exposure to the air-fuel mixture, promoting efficient combustion. The conventional construction balances performance and durability, making it suitable for secondary ignition systems in performance-oriented vehicles like the BMW M3, M5, and M6.

Technical Description and Attributes

The Denso 4085 spark plug incorporates a nickel ground electrode core and tip, providing resistance to wear and corrosion. The copper center electrode core improves thermal conductivity, while the nickel tip maintains consistent spark delivery. With a pre-gap size of 0.9 mm, this spark plug ensures optimal ignition timing. The flat seat type guarantees a secure fit and proper sealing within the combustion chamber. Its 12.00 mm thread diameter and 19.00 mm reach are designed to match the specifications required by BMW M3, M5, and M6 engines. The heat range of 22 aligns with manufacturer recommendations for these models, supporting stable engine temperatures during operation.

Compatible Vehicles and Common Applications

• Replacement spark plug for BMW M3 models requiring part number 4085
• Suitable for BMW M5 engines needing a U-groove conventional spark plug
• Compatible with BMW M6 vehicles for secondary ignition system maintenance
• Addresses issues such as misfires, rough idling, and poor fuel efficiency
• Helps restore consistent engine starting and smooth acceleration

Installation Notes and Tips

When installing the Denso 4085 spark plug, ensure the engine is cool to prevent thread damage. Use a torque wrench to tighten the spark plug to the manufacturer’s specified torque setting. Verify the pre-gap size of 0.9 mm before installation, adjusting if necessary. The 18.0 mm hex size allows for standard spark plug sockets. Proper installation will help maintain engine performance and prevent combustion chamber leaks.

Quality Assurance and Warranty

Denso spark plugs, including the 4085 model, are manufactured to meet strict quality standards for durability and performance. The materials used, such as nickel and copper electrodes, are selected for their resistance to wear and thermal stress. While specific warranty details may vary, Denso products typically come with manufacturer-backed quality assurance to support reliable operation in BMW M3, M5, and M6 vehicles.