Denso Iridium Long Life Spark Plugs SK16HR11 — 4-Pack, OEM Fit & Improved Durability

DENSO 3417 Iridium Long Life Spark Plugs (SK16HR11) are a genuine 4-pack of high-performance replacement plugs engineered for extended service life and consistent ignition.

These authentic DENSO spark plugs come as a set of four and use an iridium-tipped center electrode for improved durability and reliable spark delivery under a wide range of driving conditions. The SK16HR11 specification is built to match factory fitment and heat range requirements where DENSO recommends iridium parts for longevity and stable combustion. Free shipping within the USA and territories is included with this item.

What makes DENSO iridium plugs different from standard plugs?

Iridium plugs use a very hard, high-melting-point metal on the center electrode, which lets manufacturers make a much finer tip that delivers a more concentrated spark. That finer electrode reduces voltage demand and resists wear longer than conventional nickel electrodes, so ignition performance holds up over many miles.

• Fine iridium center electrode for precise spark
• Improved electrode life versus nickel designs
• Lower required firing voltage for consistent ignition
• Designed to meet OEM heat range specifications (SK16HR11)

How will these plugs affect vehicle performance and maintenance?

When replaced on schedule, iridium plugs help maintain steady throttle response, smooth idle and reliable starting by preserving spark quality. Because the iridium tip resists erosion, service intervals can often be extended compared with standard plugs, lowering routine maintenance frequency.

• Consistent ignition for smoother running and stable idle
• Potentially longer replacement intervals than nickel plugs
• Helps reduce misfires and rough startups when properly gapped
• Exact fitment minimizes installation issues and ensures correct heat dissipation

Are these DENSO 3417 plugs compatible with my vehicle?

The SK16HR11 specification identifies the thread size, reach, and heat range that determine compatibility; they are intended for engines that list SK16HR11 or DENSO 3417 as the proper replacement. Check your vehicle’s owner manual, existing plug markings, or an electronic parts finder to confirm correct fitment before ordering.

• SKU: DENSO 3417 – SK16HR11 specification
• Sold as a set of four plugs (1 order = 4 pieces)
• Match thread, reach, and heat range to OEM requirements
• Contact a parts specialist if unsure about compatibility

What do I get with this purchase and are there shipping details?

This listing includes four genuine DENSO 3417 iridium spark plugs packaged for retail fitment and ready for installation. The seller offers free shipping to addresses within the United States and its territories; check the product page for estimated delivery windows and return policies.

• Package contains 4 DENSO 3417 (SK16HR11) iridium spark plugs
• Free shipping across USA and territories for this item
• New, boxed components intended as direct replacements
• Keep original packaging and receipts for warranty or returns

Who is this for: Drivers, mechanics, and performance-minded vehicle owners who need a reliable OEM-grade replacement plug that prioritizes longevity and consistent spark behavior. Choose this DENSO 4-pack if your vehicle lists SK16HR11/3417 as the correct part number, if you want longer service life than standard plugs, or if you prefer genuine DENSO components for OEM compatibility and peace of mind.