The E3 Spark Plugs E3.42 Automotive Spark Plug is designed for optimal performance in domestic applications. Featuring a patented DiamondFIRE ground electrode, this spark plug increases power, reduces fuel consumption, and improves hydrocarbon emissions. With a colder heat range and Yttrium-enhanced alloy, it provides increased durability and a reduced side wire temperature. This spark plug includes a 14mm thread diameter, 0.460-inch thread reach, and 5/8-inch hex size, and is backed by a five-year or 100,000-mile manufacturer's warranty.