I know the service interval says 100,000 miles before changing the plugs....has anyone changed them early? My 300ZTT suggests a plug change every 60K but I usually change them every 15K. If you do swap them out, any suggestions as to what to use (other than factory)? TIA.

Walter

I replaced mine at 55,000. The original plugs looked really good though, I believe that they would have lasted another 40,000 easily. With gas around the $2 mark, a new set of plugs wasn't that expensive. I went with the Boush+4 plugs, but couldn't really tell any differance in performance or gas mileage. I read on some forums that the plugs are much more difficult to remove at 100,000, but I haven't any experience with that.

I always change my new car or truck plugs at the first oil change, after 2 Z06's with poorly gapped plugs from the factory it's a small price to pay, and I do it myself so there is not much of a cost factor, my Escalade plugs were pretty good, only 2 plugs were .010 too large.

did you replace them with the OEM plugs? Also, is the plug gap .060?

Walter

I replaced my plugs at about 9,000 miles.

I used the Bosch +4 and noticed a slight difference in the idle speed. The tach doesen`t fluctuate at all.

Once I waited 80,000 miles to change the plugs on a Tahoe I used to own, and I can tell you it is a pain in the a**.

I did it my self and it is a pretty straight forward procedure.

Mejia

what type of plugs should be used??

I used NGK Iridium IX plugs, I used these same plugs in my Z06's and they performed great