A-Premium Double Iridium Spark Plugs Pack of 4 — Fine-Wire, Direct-Fit for L4 Toyota/Scion/Lexus, Long Life

A-Premium Double Iridium spark plugs are a 4-pack of precision fine-wire ignition plugs engineered to deliver reliable starts and long life in compatible L4 Toyota, Scion and Lexus engines.

These spark plugs combine an iridium center electrode and iridium core with a fine-wire design to improve ignitability and sustain performance over extended mileage. They match OE specifications for thread size, reach and hex dimensions, making them a direct-fit service part for many 1.3L–2.0L inline-four engines in Corolla, Prius, C-HR, Scion and Lexus CT200h models listed in the vehicle fitment. The plugs are optimized for consistent spark delivery and are rated for long replacement intervals when used under normal driving conditions.

Will these spark plugs fit my vehicle?

Compatibility is determined by thread diameter, reach and engine application. These A-Premium plugs are designed to fit a range of late-model Toyota, Scion and Lexus L4 engines that use the DF6H-11B/95993 reference numbers.

• Thread diameter: 12.00 mm and reach 26.5 mm match listed OE specs
• Hex size: 14 mm for standard socket installation
• Confirm part numbers (DF6H-11B, 95993) and vehicle year/engine before purchase

How do these double iridium electrodes help ignition?

Double iridium construction places iridium at both the center tip and core for a more durable, stable spark surface. This reduces electrode wear and helps maintain a consistent firing characteristic over time compared with standard nickel plugs.

• Fine-wire center electrode improves spark focus and ignitability
• Iridium on tip and core resists erosion for extended service life
• 1000 ohm resistor helps suppress electrical interference with electronics

What are the key specs I need to know before installing?

Check these physical and electrical details to confirm proper installation and safe operation. They match common OE requirements for the listed vehicles and engine types.

• Gap size: 0.044 in (pre-set for typical applications)
• Insulator height: 51.00 mm; Reach: 26.5 mm
• Resistance: 1000 ohms to reduce radio/ECU interference

How often should I replace these plugs and what performance can I expect?

Double iridium plugs are designed for a long service interval when used under normal driving conditions. Replacement intervals depend on driving style, engine condition and maintenance, but these plugs are intended to offer extended durability.

• Recommended replacement range: roughly 100,000–120,000 miles under typical use
• Expect steadier starts, consistent idle and sustained combustion performance over time
• Inspect ignition system components periodically for optimal results

Who is this for: A-Premium Double Iridium Spark Plugs are aimed at owners and technicians working on compatible Toyota, Scion and Lexus inline-four engines who want an OEM-style replacement with long-life iridium electrodes. Choose these plugs if you need a direct-fit, fine-wire iridium option specified for Corolla, Prius, C-HR, Scion iM/iQ and Lexus CT200h model years listed in the fitment notes, and want to minimize service frequency while maintaining reliable ignitability and electrical compatibility.