NGK 93911 Spark Plug

NGK Iridium IX Spark Plug 93911

NGK Iridium IX Spark Plug 93911 is built for drivers servicing Mercedes-Benz, Smart, Kia, Mitsubishi, and Dodge applications that call for a precise 0.032-inch gap. With an iridium center electrode, nickel ground electrode, and copper core construction, this plug supports stable ignition performance and consistent combustion in a wide range of OE-style applications.

Key Features

• Iridium center electrode tip for fine-wire ignition performance
• Nickel ground electrode with taper-cut tip design
• Copper core center electrode for efficient heat transfer
• Pre-gapped at 0.032 inches for many listed applications
• 5,000 ohm resistance for ignition system compatibility
• Flat seat design with 12 mm thread diameter and 5/8 hex
• NGK part number 93911, also identified as LKR7AIX

Product Details

The NGK Iridium IX Spark Plug line is engineered for precise spark delivery and dependable service across import and domestic vehicles. NGK’s long OE supply history and broad North American coverage make this plug a practical choice for maintenance on vehicles such as the Mercedes-Benz C300, E350, ML350, SL550, and Smart Fortwo. The iridium tip helps maintain a consistent spark profile, while the copper core and nickel ground electrode support heat management and durability in everyday driving.

This part cross-references DENSO Auto Parts 5353 and Autolite XP5701 for the same application. Search terms such as NGK 93911 spark plug, Mercedes-Benz C350 spark plug replacement, and Smart Fortwo iridium spark plug are commonly associated with this part.

What It Helps Address

• Rough idle caused by worn spark plug electrodes
• Hard starting from weak or inconsistent spark output
• Misfire conditions related to plug wear or incorrect gap
• Reduced throttle response from degraded ignition performance
• Maintenance replacement for high-mileage ignition service

Installation Notes

Verify the vehicle-specific gap before installation. Many listed applications call for a 0.032-inch gap, while the Smart Fortwo listing notes a 0.036-inch gap. Confirm thread diameter, reach, seat type, and heat range against the original plug specification before service. Use proper spark plug removal and torque procedures to avoid thread damage or ignition issues.

Compatible With 2005-2015 Mercedes-Benz SLK350, 2006-2011 Mercedes-Benz E350, 2008-2012 Mercedes-Benz C300, and other listed Mercedes-Benz, Smart, Kia Soul, Mitsubishi Outlander, and Dodge Sprinter applications. Fits 2008-2011 Mercedes-Benz ML550, 2007-2012 Mercedes-Benz GL450, and 2008-2015 Smart Fortwo according to the provided vehicle data.

Quality Assurance

NGK is a major OE spark plug supplier with more than 80 years of automotive manufacturing experience. The brand’s OE-focused engineering and North American distribution network support consistent product quality for ignition service across a broad range of vehicles.