My Tahoe 5.3 has just turned 47K on her. When should the plugs be change?? I have no running problems that Im aware of. I usually change plugs around 30K, but this new deal with the car makers saying 100K tune ups just doesnt set right with me. Am I missing something?? If I do change them whats the best to put in??

 

This is just me, pull a few random plugs, if they look good, stickem back in a roll with it,..

John

 

Stock plugs should be iridium plugs and they are good for high mileage intervals.
As Mangled stated, just pull a couple and see if that will settle your curiosity.