I have researched the longest life plug and best perfomance option for the 1MZ-FE and Iridium is it from NGK at any rate...when you check the NGK site in the states (they have Avalons and camrys too) they recommend the Iridium plug but these only come in single electrode. Under the bonnet of my Avalon it specifically says only use dual electrode plugs why?Camry the same? Apparently the iridium plugs are good for 111,000 miles or at least twice as long as the Platinum and to those who have changed the rear plugs you would know why this is as important as perfomance gain. any ideas guys?