U-Groove design provides better ignitability for increased engine efficiency.

Product Features:

• Patented U-groove ground electrode design fires leaner mixtures than conventional plugs
• Precision machine-rolled threads reduce seizing and cross-threading in delicate aluminum heads
• Wide range of part numbers for thousands of applications, including classic and collector cars
• Lasts twice as long as most conventional plugs
• 100% pre-fired to assure reliable operation
• U-Groove Conventional