At 85K miles our RX330 is running fine. I'm having the 90K service (timing belt, water pump, belts, etc.) done next service and I'm thinking about having the plugs replaced. The manual shows to replace them at 120K miles.

Has anyone actually experienced plugs seizing up after 100K miles? I think this would be the main reason for replacing them sooner than 120K miles. My thinking is to replace them now because I'll have the benefit of driving on new plugs now and I'm sure to sell the car before new plugs are needed again. And I'm pretty sure we'll have the car past 120K miles.

What kind of plug does Toyota/Lexus use for the replacement plugs? Are they Iridium? Do you recommended one plug over another? Fuel mileage, not performance, is my main concern.

Thanks for your comments.

 

That timing belt will go way into the hundred thousand mile range.Plugs are good for 120,000.I would do both @ 120K

 

^^With the above. The plugs are platinum tipped, no need to worry. Timing belt is at 120K. You're still fine. Think about it when you hit more than 100K. Enjoy your car for now.

 

Use the recommended plugs per the manual, it is safe.