NGK 3784 Spark Plug

NGK Laser Platinum Spark Plug 3784

NGK Laser Platinum Spark Plug 3784 is an OE-style replacement spark plug built for stable ignition performance and long service life. It uses a platinum center electrode, a nickel ground electrode, and a copper core to support consistent spark delivery in a wide range of GM, Cadillac, Pontiac, Saab, Hummer, and select Ford applications.

With a pre-gap of 0.040 in., a tapered seat, and a 5,000 ohm resistor, this plug is specified for many vehicles that call for precise ignition control and dependable cold starts. The NGK 3784 is also listed under part number PTR5D-10.

Key Features

• Platinum center electrode tip for durable spark performance
• Copper core center electrode for efficient heat transfer
• Nickel ground electrode with standard configuration
• Pre-gapped to 0.040 in. for listed applications
• 5,000 ohm resistor to help control electrical noise
• Tapered seat, 14 mm thread diameter, 5/8 in. hex
• NGK part number PTR5D-10; stock number 3784

Product Details

NGK is a major OE spark plug supplier in North America, and this Laser Platinum Spark Plug line is built around original-equipment service expectations for durability and operational consistency. The 3784 is used across many Chevrolet Silverado, Tahoe, Corvette, Camaro, and Express models, along with GMC Sierra, Yukon, and Savana applications. It also appears in fitment for Cadillac Escalade, Pontiac GTO, and select Buick, Hummer, Saab, Isuzu, Aston Martin, and Ford vehicles.

This part cross-references DENSO Auto Parts 4511 for the same application.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent ignition output
• Misfire conditions related to plug wear or incorrect gap
• Reduced throttle response from weak spark delivery
• Service intervals where OE-style replacement is required

Installation Notes and Tips

Verify engine application before ordering and confirm the plug gap matches the vehicle specification. Many listed applications call for a 0.040 in. gap, while some Ford fitments specify 0.044 in. and dual-plug service. Use the correct torque procedure for the cylinder head material and inspect ignition coils, boots, and wires during service.

Compatible With many 1991-2017 Chevrolet Silverado, Tahoe, Corvette, Camaro, and Express applications; 2000-2017 GMC Sierra, Yukon, and Savana applications; and 2002-2014 Cadillac Escalade applications. Additional coverage includes select Pontiac, Buick, Hummer, Saab, Isuzu, Aston Martin, and Ford models.

Quality Assurance

NGK backs this spark plug with its OE manufacturing legacy and global production and distribution network. The brand’s long-standing role as an original equipment supplier supports consistent build quality and application-specific fitment for secondary ignition service.