Denso 3048 Spark Plug

Denso 3048 U-Groove Spark Plug Overview

The Denso 3048 is a conventional spark plug built for secondary ignition service in select Dodge, Plymouth, Mitsubishi, and Suzuki applications. Its U-Groove ground electrode design helps improve ignitability for more consistent combustion and engine efficiency.

Compatible With 1984-1986 Dodge Conquest, 1984-1986 Plymouth Conquest, 1984 Mitsubishi Starion, and 1979-1980 Dodge Colt, this plug is a direct-fit option for vehicles specified with the listed OE-style application.

Key Features

• Part number 3048 from Denso U-Groove Conventional
• U-Groove ground electrode tip design for improved spark exposure
• 5000 ohm resistor for ignition noise suppression
• Copper center electrode core for stable heat transfer
• Nickel center and ground electrode tip materials
• Standard ground configuration with a flat seat
• 14.00 mm thread diameter, 19.00 mm reach, and 20.6 mm hex size
• Manufacturer heat range 20 with a 1.0 pre-gap size

Product Details

Denso’s U-Groove Conventional line focuses on dependable ignition performance in a traditional spark plug format. The U-shaped ground electrode helps expose the spark kernel more effectively, which supports cleaner firing and smoother engine operation in the specified applications. The Denso 3048 uses a copper core center electrode for efficient heat dissipation, while the nickel electrode materials provide a durable firing surface for everyday service.

This part cross-references DENSO Auto Parts W20EPR-U10 and Suzuki 09482-00421 for the same application.

What It Helps Address

• Hard starting caused by worn or inefficient spark plugs
• Rough idle from weak or inconsistent ignition
• Misfire conditions related to degraded plug electrodes
• Reduced combustion efficiency in aging secondary ignition systems
• Maintenance replacement for specified Dodge Conquest, Plymouth Conquest, Mitsubishi Starion, and Dodge Colt applications

Installation Notes

Verify thread diameter, reach, seat type, and heat range against the vehicle’s service specifications before installation. The Denso 3048 is a flat-seat spark plug with a 14.00 mm thread diameter, 19.00 mm reach, and 20.6 mm hex size, so proper torque and plug socket selection matter during service. Check the gap against the engine specification before use, even when a pre-gap size is listed.

Quality Assurance

Denso manufactures this spark plug as part of its U-Groove Conventional ignition line, using OE-style construction and specified electrode materials for consistent service in the listed applications. Confirm fitment for 1984-1986 Dodge Conquest, 1984-1986 Plymouth Conquest, 1984 Mitsubishi Starion, and 1979-1980 Dodge Colt before ordering.