NGK 6858 Spark Plug

Overview of NGK Laser Iridium High Ignitability Spark Plug 6858

The NGK Laser Iridium High Ignitability Spark Plug 6858 is engineered for reliable ignition performance in select Lexus models. Designed with advanced materials and a unique electrode configuration, this spark plug supports efficient combustion and consistent engine operation.

• Part Number: 6858 (Dfh6b-11a)
• Compatible with Lexus GS300, GS350, GS450h, GS460, IS250, IS300, IS350, IS F, LS460, LS600h, RC300, RC350
• Iridium center electrode tip for enhanced durability
• Dual fine ground electrodes with hybrid configuration
• Nickel ground electrode core and copper center electrode core
• Pre-gap size of 0.044 inches for optimized spark
• Flat seat type with 14mm thread diameter and 26.5mm reach
• Non-removable nut electrical terminal type
• Manufacturer heat range rating of 6

About the Laser Iridium High Ignitability Spark Plug Line

The NGK Laser Iridium High Ignitability Spark Plug line focuses on delivering improved ignition efficiency through a combination of iridium-tipped center electrodes and a dual fine electrode design. This configuration reduces voltage requirements and promotes stable combustion, which is critical for modern engines such as those found in Lexus GS and IS series vehicles. The hybrid ground electrode design further enhances ignitability while maintaining electrode durability.

Technical Features and Benefits

This spark plug features a 5000 ohm resistance to suppress electrical noise and protect vehicle electronics. The center electrode core is made of copper, providing excellent thermal conductivity, while the iridium tip ensures long service life and consistent spark delivery. The ground electrode consists of three nickel core electrodes arranged in a hybrid configuration with dual fine tips, which improves ignition reliability and fuel efficiency. The pre-gap size of 0.044 inches is factory set to optimize spark performance for the specified Lexus models.

Applications and Problem Solving

• Compatible with Lexus GS300, GS350, GS450h, GS460, IS250, IS300, IS350, IS F, LS460, LS600h, RC300, and RC350 models
• Addresses misfires caused by worn or damaged spark plugs
• Improves cold start performance and throttle response
• Helps reduce engine hesitation and rough idling
• Supports efficient fuel combustion to maintain engine power

Installation Notes and Tips

• Ensure the spark plug gap is set to 0.044 inches before installation if adjustment is necessary
• Use a 5/8 inch hex socket for proper torque application
• Apply anti-seize compound sparingly on threads to prevent galling
• Torque to manufacturer specifications to avoid damage to the flat seat
• Verify compatibility with the specific Lexus model and engine variant before installation

Quality Assurance and Warranty

NGK spark plugs are manufactured to meet strict quality standards, ensuring consistent performance and durability. The Laser Iridium High Ignitability Spark Plug 6858 undergoes rigorous testing for heat range, electrode wear, and electrical resistance. While specific warranty terms may vary, NGK typically offers coverage against manufacturing defects. Consult vehicle or part documentation for detailed warranty information.