Denso 3125 Spark Plug

Overview of Denso 3125 Spark Plug for Mercedes-Benz and Saab

The Denso 3125 spark plug is engineered for reliable ignition performance in select Mercedes-Benz and Saab vehicles. 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 0.8 mm for precise ignition timing
• Flat seat type with 19.00 mm reach and 14.00 mm thread diameter
• Hex size of 16.0 mm for standard installation tools
• Manufacturer heat range rating of 20 suitable for specified vehicle models

Detailed Description of Denso U-Groove Conventional Spark Plug

The Denso 3125 spark plug belongs to the U-Groove Conventional product line, which features a unique U-groove ground electrode tip design. This design increases the spark exposure area, promoting better ignition and combustion efficiency. The spark plug’s construction includes a nickel ground electrode core and tip, providing resistance to wear and corrosion. The center electrode combines a copper core for excellent thermal conductivity with a nickel tip to maintain durability under high temperatures. With a pre-gap size of 0.8 mm and a flat seat type, this spark plug ensures consistent spark delivery and proper sealing within the combustion chamber. Its 19.00 mm reach and 14.00 mm thread diameter make it compatible with specific Mercedes-Benz and Saab models, including the Mercedes-Benz S420 and Saab 900 and 9000 series.

Compatible Vehicles and Applications

This Denso 3125 spark plug is compatible with the following vehicles:

• Mercedes-Benz S420
• Saab 900
• Saab 9000

It is designed to address ignition-related issues such as:

• Engine misfires and rough idling
• Reduced fuel efficiency due to incomplete combustion
• Difficulty starting the engine
• Increased exhaust emissions
• Loss of engine power under load

Installation Notes and Tips

When installing the Denso 3125 spark plug, ensure the following:

• Verify the correct gap of 0.8 mm before installation
• Use a 16.0 mm hex socket for proper torque application
• Apply anti-seize compound on threads if recommended by the vehicle manufacturer
• Torque to manufacturer specifications to avoid damage to the spark plug or cylinder head
• Inspect the spark plug seat to ensure a flat and clean surface for proper sealing

Quality Assurance and Warranty

Denso manufactures the 3125 spark plug to meet strict quality standards, ensuring consistent performance and durability. The use of high-quality materials such as nickel and copper in the electrode construction supports long service life. While specific warranty details may vary, Denso products typically come with manufacturer-backed quality assurance to support reliability in secondary ignition applications.