Quote Originally Posted by Pikey View Post
Really?? Multiple times I have seen AC delco plugs with 75,000 miles or more that still look new. They are actually still within the gap spec most the time. Are you talking about vehicles with major mods?
I agree with Pikey mine were factory with 197,000 miles on them when I removed them and they were close to factory gaps. Of course my Tahoe was one of the first GMs to use stock platinum plugs rated for 100,000 miles before they needed to be checked or changed. One broke when removing but that was because I didn't use enough penetrating oil. Others came out with out a problem at the shop that I then brought the truck too so they could remove the broken plug.