NGK 3903 Spark Plug - Intake Side

Reliable Ignition Performance for Multiple Vehicle Makes

The NGK Iridium IX Spark Plug 3903 (Part Number Bpr6eix-11) delivers consistent ignition performance designed for a wide range of vehicles including Chevrolet, Honda, Ford, and Nissan models. Engineered with durable materials and precise specifications, this spark plug supports efficient combustion and engine responsiveness.

• Iridium center electrode tip for enhanced durability and ignition
• Taper cut ground electrode tip design for improved spark exposure
• Copper core center electrode for optimal conductivity
• Standard ground configuration with nickel ground electrode core
• Non-removable nut electrical terminal type for secure connection
• Pre-gap size of 0.044 inches for precise spark gap
• Flat seat type with 14mm thread diameter and 0.75 inch reach
• Hex size 13/16 inch for easy installation
• Manufacturer heat range 6 suitable for various engine conditions

About the NGK Iridium IX Spark Plug Line

The Iridium IX Spark Plug line from NGK is designed to provide improved ignition performance and longer service life compared to conventional spark plugs. Featuring an iridium center electrode tip, these plugs offer enhanced wear resistance and stable spark delivery. The 3903 model incorporates these benefits with a copper core for efficient electrical conductivity and a taper cut ground electrode to optimize spark exposure, making it suitable for many domestic and import vehicles.

Technical Details and Compatibility

This spark plug features a single ground electrode with a nickel core and a non-removable nut terminal type, ensuring reliable electrical connection. The pre-gap is set at 0.044 inches, supporting consistent ignition timing. With a flat seat and 14mm thread diameter, it fits securely in compatible engines. The 0.75 inch reach and 13/16 inch hex size facilitate proper installation and maintenance.

Applications and Problem Solving

• Restores engine misfire issues in Chevrolet, Honda, Ford, and Nissan vehicles
• Improves fuel efficiency by ensuring consistent spark delivery
• Reduces rough idling and hesitation during acceleration
• Supports stable combustion in vehicles like the Honda Accord, Ford Mustang, and Nissan 200SX
• Addresses ignition performance degradation in older or high-mileage engines

Installation Notes and Tips

Before installation, verify compatibility with your vehicle’s make and model, such as the Mitsubishi Eclipse or Subaru Impreza. Use a torque wrench to tighten the spark plug to manufacturer specifications to avoid damage. The 13/16 inch hex size allows for standard spark plug socket use. Ensure the pre-gap is maintained at 0.044 inches if adjustment is necessary. Avoid over-tightening to protect the flat seat and thread integrity.

Quality Assurance and Warranty

NGK spark plugs, including the Iridium IX 3903, are manufactured to meet strict quality standards for durability and performance. The use of iridium and copper materials ensures long service life and reliable ignition. While specific warranty details may vary, NGK products typically come with manufacturer-backed quality assurance to support customer confidence in fitment and function.