NGK LFR6AIX-11 Iridium Spark Plugs (4 plugs) Stock No 6619

Upgrade your ignition system with this set of 4 NGK LFR6AIX-11 Iridium IX spark plugs, stock number 6619. Designed for strong ignitability, stable spark performance, and long-lasting durability, NGK Iridium IX plugs are a popular upgrade over standard nickel alloy spark plugs.

The LFR6AIX-11 features a 0.6mm fine-wire iridium center electrode, tapered-cut ground electrode, solid copper core, and trivalent metal plating. The fine-wire iridium tip helps create a consistent spark, while the tapered-cut ground electrode helps reduce quenching for improved ignition efficiency and throttle response.

This plug also uses a copper core for heat dissipation and trivalent plating for corrosion resistance and easier installation/removal. This listing includes 4 spark plugs, making it a convenient set for many 4-cylinder applications that require NGK LFR6AIX-11 / 6619 spark plugs.

Features

• Genuine NGK Iridium IX spark plugs

• Part number: LFR6AIX-11

• NGK stock number: 6619

• Sold as a set of 4 plugs

• Manufacturer heat range: 6

• Fine-wire iridium center electrode

• 0.6mm iridium tip

• Tapered-cut ground electrode

• Solid copper core for heat dissipation

• Trivalent metal plating for corrosion and anti-seize protection

• Resistor type plug

• Gasket / flat seat design

• Recommended for performance, modified, or OE nickel alloy spark plug upgrade applications

Spark Plug Specs

Part Number: LFR6AIX-11
Stock Number: 6619
Plug Type: NGK Iridium IX
Thread Size: M14 x 1.25
Reach: 26.5mm
Hex Size: 5/8 in / 16mm
Pre-Gap: 1.1mm / 0.044 in
Seat Type: Gasket / flat seat
Heat Range: 6
Terminal Type: Non-removable nut
Resistor Type: Yes

Important Fitment Note

Confirm vehicle fitment, spark plug heat range, reach, and gap requirements before installation. Spark plug selection can vary based on engine, modifications, fuel type, compression, boost level, and tuning setup.

What’s Included

• 4 NGK LFR6AIX-11 Iridium IX spark plugs

• NGK stock number: 6619