NGK 91731 Laser Iridium Spark Plug for 2016-2025 Porsche 718 2.5L H4

Vehicle Fitment

• 2016-2025 Porsche 718 Cayman S (982), 2.5L Turbo H4, RWD
• 2017-2025 Porsche 718 Cayman GTS (982), 2.5L Turbo H4, RWD
• 2016-2025 Porsche 718 Boxster S (982), 2.5L Turbo H4, RWD
• 2017-2025 Porsche 718 Boxster GTS (982), 2.5L Turbo H4, RWD

Fitment Notes

• OE-style Laser Iridium spark plug.
• Fits only 2.5L turbocharged H4 engine applications listed above.
• Does not fit 2.0L, 4.0L, GT4, Spyder, or other non-listed Porsche engines.
• Sold individually; verify engine quantity required before ordering.

Features

• NGK Laser Iridium OE replacement spark plug.
• Fine-wire iridium center electrode improves ignitability.
• Laser-welded platinum ground electrode enhances service life.
• High resistance to electrode wear under extreme combustion temperatures.
• Pure alumina ceramic insulator provides superior dielectric strength.
• Copper core promotes efficient heat dissipation.
• Factory-specified heat range and gap for compatible Porsche applications.
• Designed to deliver reliable cold starts, smooth idle, and consistent performance.

Specifications

• Manufacturer: NGK
• Part Number: 91731
• NGK Stock No.: 91731
• Series: Laser Iridium
• Plug Type: SILKGR9A7EG
• Thread Size: M12 x 1.25
• Hex Size: 14 mm Bi-Hex
• Reach: 26.5 mm (1.043 in.)
• Seat Type: Flat Gasket
• Heat Range: NGK 9
• Factory Gap: 0.7 mm (0.028 in.)
• Resistor: Yes (5 kΩ)
• Position: Engine Spark Plug

Included Components

• 1x NGK 91731 Laser Iridium Spark Plug

Product Description

The NGK 91731 Laser Iridium Spark Plug (SILKGR9A7EG) is an OE-quality replacement engineered for select Porsche 718 Cayman and Boxster models equipped with the 2.5L turbocharged flat-four engine. Its fine-wire iridium center electrode and laser-welded platinum ground electrode provide exceptional ignition efficiency, excellent combustion stability, and long-lasting durability under demanding operating conditions.

Manufactured to NGK's original equipment standards, this spark plug helps maintain reliable starts, smooth engine operation, and consistent performance throughout its service life. The copper core and high-strength ceramic insulator improve heat transfer and electrical insulation, making it an ideal replacement during scheduled maintenance while preserving factory ignition performance.