These NGK Iridium IX 1 Step Colder Spark Plugs are a top - notch choice for your Subaru. They fit multiple Subaru models including the 2006 - 2014 WRX, 2004 - 2021 STi, 2005 - 2009 Legacy GT, 2005 - 2009 Outback XT, and 2004 - 2008 Forester XT. Sold in a set of 4, these spark plugs come with a host of great features. The trivalent metal plating offers excellent anti - corrosion and anti - seizing properties. Corrugated ribs stop flashover, and the pure alumina silicate ceramic insulator provides strong strength and efficient heat transfer. The copper core helps remove heat, and triple seals prevent leakage. With a lifespan of 50k miles and a 60 - day manufacturer warranty, they're reliable. The spark plug has a 14mm thread diameter, 1.25mm thread pitch, flat seat type, 26.5mm reach, 5/8' (16mm) wrench diameter, solid terminal type, and a.031' (0.8mm) gap. The center electrode is made of iridium tip and copper core, while the ground electrode is nickel with a taper - cut shape. It has a 5k Ohm resistor and a manufacturer heat range of 7. Torque specs are 18 - 25.3 lb. ft. for cast iron and 18 - 21.6 lb. ft. for aluminum. Compared to platinum, NGK Iridium offers more durability, a higher melting point, better anti - oxidation and anti - erosion for the center electrode, improved ignition, superior anti - fouling, and lower required voltage. One step colder plugs are great for heavily modified cars. They'll make your Turbo Subaru run smoother and boost power through increased efficiency and heat resistance. You can choose between stock heat and one step colder for cars with about 100 more horsepower than stock. Note that iridium plugs can use larger gap settings with less voltage. Some customers may want to regap them, but be careful as a slide - type plug gapper can damage the fragile iridium tip. Import Image Racing is an authorized dealer, so you're guaranteed authentic products with manufacturer warranty.
Using these NGK Iridium IX 1 Step Colder Spark Plugs is straightforward. First, make sure your car engine is cool before you start the replacement process. You'll need the right tools, like a socket wrench that matches the 5/8' (16mm) wrench diameter of the spark plugs. Carefully remove the old spark plugs and install the new ones. Tighten them according to the torque specs - 18 - 25.3 lb. ft. if your engine is made of cast iron, and 18 - 21.6 lb. ft. if it's aluminum. When it comes to maintenance, these spark plugs are built to last 50k miles, but it's a good idea to check them periodically. Look for signs of fouling or corrosion. If you notice your car misfiring or having trouble starting, the spark plugs might be the issue. However, be very careful if you think about regapping the plugs. Iridium is fragile, and using a slide - type plug gapper can damage the tip. If you're unsure, it's best to take your car to a professional mechanic. Also, remember that these plugs are covered by a 60 - day manufacturer warranty, so if you have any problems within that time, you can contact us for assistance.
