Accel U-Groove Copper Spark Plugs

Accel U-Groove spark plugs represent decades of proven ignition technology, built on a patented U-shaped ground electrode design that has set the standard for high-performance spark plugs since the mid-1980s. Engineered for enthusiasts who demand reliable, efficient ignition in both street and high-performance applications, every plug in this line delivers a hotter, fuller spark for more complete combustion of the air/fuel mixture.

Key Features:

• Patented U-Groove ground electrode — minimizes flame dissipation and develops a larger spark nucleus for faster, more complete combustion
• Copper core construction — delivers superior heat dissipation compared to platinum and iridium, reducing the risk of misfires under demanding conditions
• Copper-glass seal bond insulator — provides a gas-tight seal, preventing leakage even in high-compression engines
• Electric heat seal — ensures a stable heat range for consistent, uniform performance across all operating conditions
• Sintered alumina insulator — eliminates flashover and protects against overheating
• Machine-rolled threads — allow for precise thread engagement and proper torque retention to protect cylinder heads
• Gapable electrode design — allows adjustment for naturally aspirated or forced induction applications

Backed by over 40 years of racing development and street performance testing, Accel U-Groove copper spark plugs are trusted by performance enthusiasts on the street, strip, and track. The result is better throttle response, reduced fouling and misfiring, a faster burn rate, and increased power at high RPM — in a proven, reliable package.