The Toyota service writer told me they recommend 30k spark plug changes on the V8 as part of their 30k service. It's better for the engine, he said. I think the service writer knows what a 4Runner is, and I think he is pretty sure it's made by Toyota because they keep showing up for service, but beyond that he carries a flash light on his belt, in case he looses his a$$. He did know that the plugs were different than the V6 and said that the V8 plugs were uranium plugs and for the best mileage they changed them at 30k miles. I guess my V8 is a different model because it has iridium plugs and they last a lot longer than 30k miles. And I guess that other customers are paying for this guy's learning curve. Other service writers have to be better informed than this guy. The only thing I did was buy some Toyota parts. After seeing the dealer's service department in action, I'm doing the service myself. And I don't want any uranium plugs in my engine.