2011 Nissan GT-R Owner's Manual - Page 266

SPARK PLUGS replaced or adjusted by a GT-R certified NISSAN dealer. 2. Have the belts checked regularly for condition and tension in accordance with the maintenance schedule in your NISSAN Service and Maintenance Guide. WARNING Be sure the engine and the ignition switch are off and that the parking brake is engaged securely. NOTICE Be sure to use the correct socket to remove the spark plugs. An incorrect socket can damage the spark plugs. REPLACING SPARK PLUGS If replacement is required, see a GT-R certified NISSAN dealer for servicing. Iridium-tipped spark plugs It is not necessary to replace the iridium-tipped spark plugs as frequently as the conventional type spark plugs since they will last much longer. Follow the maintenance schedule in NISSAN Service and Maintenance Guide, but do not reuse them by cleaning or regapping. Always replace spark plugs with recommended or equivalent ones. 8-18 Maintenance and do-it-yourself