NGK has created their recommendations based on the general consensus of most engine manufactures.If using anti-seize compound, use sparingly and reduce torque by 30%.Torque recommendations are for spark plugs with new gaskets.1/12-1/8 turn on plugs with a tapered seat. If a torque wrench is unavailable, finger tighten the spark plug, then use a plug wrench to tighten. If a recommendation has been made, it will appear under the "Specifications" heading. While viewing the part detail page, click on the "specs" tab. To find NGK's recommended torque setting, please enter the spark plug number in the search box. Then tighten the plug as specified below: With a Torque Wrench: Screw in the spark plug finger tight until the gasket meets the cylinder head. Proper Tightening ProcedureĬlean the spark plug threads and ensure the cylinder head is clean of debris. Either of these would result in elevated combustion chamber temperatures, followed by pre-ignition and detonation.
Under tightening will prevent the spark plug from being properly seated on the cylinder head, resulting in insufficient contact with the head to transfer heat. Over tightening can cause damage to the threads in the cylinder head and the threads of the spark plug, stress the spark plugs internal seal, or fracture the spark plugs insulator. It is essential to tighten a spark plug to the specified turning angle or torque setting as torque directly impacts a spark plugs ability to remove heat from the combustion chamber.