NGK 91731 Spark Plug

NGK Laser Iridium Spark Plug for Porsche 718

NGK 91731 is a Laser Iridium High Ignitability spark plug built for select Porsche 718 Boxster and Porsche 718 Cayman applications. It is specified for factory service intervals on covered vehicles and supports OE-style ignition performance for the 2017-2024 Porsche 718 platform.

Key Features

• Laser Iridium High Ignitability design for precise spark delivery
• OE-focused spark plug for select Porsche 718 Boxster and 718 Cayman models
• Factory service interval coverage for 40,000 miles on listed applications
• Gap specification noted at 0.028 in. for 2017-2020 applications
• NGK part number 91731; OE reference SILKGR9A7EG

Product Details

NGK 91731 is part of the Laser Iridium High Ignitability spark plug line, a product family built around fine-wire iridium construction and OE-level ignition requirements. NGK supplies spark plugs to domestic and import vehicle manufacturers and applies that OE experience to replacement parts for the Porsche 718 Boxster and Porsche 718 Cayman. This part cross-references NGK 91731 for the same application.

Compatible With 2021-2024 Porsche 718 Boxster and 2021-2024 Porsche 718 Cayman, N/A. Compatible With 2017-2020 Porsche 718 Boxster and 2017-2020 Porsche 718 Cayman, N/A, with OE spark plug high-ignitability requirements and a 0.028 in. gap noted in the fitment data. Search terms such as Porsche 718 Boxster spark plug replacement, Porsche 718 Cayman NGK 91731, and 2017-2024 Porsche 718 Laser Iridium spark plug align with this application.

What It Helps Address

• Misfires caused by worn or degraded spark plug electrodes
• Hard starting related to weak ignition output
• Rough idle from inconsistent spark delivery
• Loss of throttle response from aged plugs
• Service interval maintenance on covered Porsche 718 models

Installation Notes and Tips

Verify engine application against the vehicle service information before installation. For 2017-2020 Porsche 718 Boxster and Cayman listings, confirm the 0.028 in. gap specification shown in the fitment notes. Replace plugs on a cool engine, follow the manufacturer torque procedure, and inspect ignition components during service.

Quality Assurance

NGK is a long-standing OE spark plug supplier with North American manufacturing, inventory, and distribution support. The brand’s OE background and application-specific engineering make NGK 91731 a direct-fit service part for the listed Porsche 718 Boxster and Porsche 718 Cayman vehicles.