NGK Iridium IX Spark Plug Box of 4 (TR4IX)

This is a box of four NGK Iridium IX spark plugs, part number 7300, with the designation TR4IX. These plugs are designed to give you a more consistent spark, which can lead to better acceleration and improved fuel efficiency compared to standard plugs. They fit a wide range of vehicles, including many Buick, Chevrolet, and Pontiac models from the late 80s through the early 2010s.

The key to these plugs is the fine iridium tip on the center electrode. Iridium is a very hard metal, six times harder than platinum, and it has a very high melting point. This means the electrode can be made much finer, requiring less voltage to jump the gap and creating a stronger spark. This fine tip also helps with starting and idling, and the tapered cut on the ground electrode helps prevent fouling. The metal plating on the plug body helps resist corrosion and makes them easier to remove later on.

These are a good choice if you're looking to upgrade from standard nickel alloy plugs, especially if your vehicle has been modified or you're just aiming for a bit more performance and durability from your ignition system.