I hate to admit it but my wife's Honda Pilot has 260,000 miles. 3 of the plugs are original still. When I changed the three that were in the front that were easy to get to, they were perfect still at 250,000 miles. Ngk Iridium rocks. They aren't cheap they're about $12 a piece though.. one of these days I'll get around to doing the other three if I remember. The Honda V6 engine still purrs like new.