HKS SUPER FIRE RACING M40i

HKS is well-known for its performance tuning parts, and their Super Fire Racing spark plugs are a popular choice for enthusiasts looking for improved ignition performance. The M40i is designed to handle the demands of modified engines, offering a strong spark for efficient combustion. Its construction focuses on durability and consistent performance, making it a solid option for those who push their vehicles.

These plugs feature a fine-wire iridium center electrode, which helps to create a hotter spark and improve ignitability. The ground electrode is also designed for optimal spark plug gap retention, ensuring that the gap stays consistent over time. This attention to detail in the design helps to maintain smooth idling and responsive acceleration, even under demanding conditions. If you're rebuilding or tuning your engine, these plugs are built to keep up.