This is the factory spark plug as installed in the 2018 Subaru WRX STI Type RA and 2019 Subaru WRX STI. The main differences are a heat range that is one-step cooler as well as a slightly tighter gap than previous factory spark plugs. These serve as a factory replacement for the 2018 STI Type RA and 2019 STI and a great upgrade for modified 2.5L Turbocharged Subarus.

Why?

A good quality spark plug goes a long way in ensuring your car's engine is running smoothly. For years, tuners have been using an alternate solution on cars that needed a tighter gap and cooler heat range. Now available as an off-the-shelf plug, this takes the guess work out of replacing or upgrading your Subaru's spark plugs.