Genuine VW/Audi spark plug for Audi RS7 and other models with 4.0T V8. Also a common upgrade for VW/Audi cars with Generation 3 2.0T TSI engines such as the MK7 GTI, Golf R, and Audi S3. It is one heat range colder than the factory plugs found in the 2.0T engines. This plug is manufactured for VW/Audi by NGK. It is a double Iridium design. Iridium is the most corrosion resistant metal and very stable when exposed to methanol, so it's the plug of choice for Gen 3 2.0T owners using water/methanol injection.