NGK 91768 Spark Plug

NGK Iridium IX Spark Plug for Performance Ignition

NGK Iridium IX Spark Plug 91768 is built for drivers who want precise ignition response, stable idle quality, and durable performance in modern engines. This iridium spark plug uses a fine-wire center electrode and a tapered cut ground electrode to support strong starting, clean throttle response, and consistent combustion.

Compatible With select Cadillac XT5, Cadillac XT6, Chevrolet Blazer, Chevrolet Camaro, GMC Acadia, Chevrolet Colorado, GMC Canyon, Buick Regal Sportback, Cadillac CT6, Buick LaCrosse, Cadillac ATS, and Cadillac CTS applications, this plug is a direct-fit ignition service part for a wide range of GM vehicles. Part number 91768 is also referenced as LNAR7AIX.

Key Features

• Single iridium center electrode for long-lasting electrode durability
• Fine-wire center electrode design for strong ignitability
• Taper cut ground electrode for improved starting, idling, and throttle response
• Resistor type plug with 5,000 ohm resistance
• Performance grade construction for modern ignition systems
• Pre-gapped at 0.028 in / 0.7 mm
• M12 x 1.25 thread size, 14 mm hex, tapered seat
• Nickel ground electrode with copper core center electrode

Iridium IX Product Line Details

NGK Iridium IX plugs are aimed at performance-focused street use where ignition consistency matters. The iridium alloy center electrode handles high heat well, while the tapered ground design helps support smoother combustion behavior under daily driving and load changes. For applications that call for a premium ignition upgrade, 91768 offers a technical step up from conventional plugs.

Detailed Description

NGK 91768 is engineered for engines that benefit from a fine-wire iridium tip, a mid-projection design, and a tapered seat configuration. The ceramic insulator, nickel ground tip, and J-gap layout work together to promote stable spark delivery and anti-fouling performance. This plug is a practical choice for owners servicing Cadillac XT5 and XT6, Chevrolet Camaro and Blazer, or GMC Acadia, Colorado, and Canyon models that specify this application.

This part cross-references Edelmann 91768 for the same application.

What It Helps Address

• Hard starting caused by worn or weakened spark plugs
• Rough idle from inconsistent spark delivery
• Throttle hesitation during acceleration
• Misfire concerns related to aged ignition components
• Fuel economy loss from incomplete combustion

Installation Notes and Tips

• Verify the engine-specific gap requirement before installation; listed fitments note 0.030 in or 0.036 in depending on vehicle application.
• Confirm thread size, reach, and tapered seat match the original specification.
• Use proper spark plug socket tools to avoid damaging the ceramic insulator.
• Inspect ignition coils and boots during service to help maintain consistent performance.
• Follow the vehicle manufacturer’s torque specification for final installation.

Quality Assurance

NGK is a recognized ignition component manufacturer, and this Iridium IX plug is built with a single iridium metallurgy, resistor design, and performance-focused electrode construction for dependable service in modern gasoline engines.