I think that DRM2004 has been reading the horror stories of people having to replace cylinder heads because of plugs getting stuck in the heads or breaking off. The issue is that carbon build up is causing the plugs to get stuck if you leave them in too long. Some have blamed the unusual plug design some have blamed it on using cheap fuel that leaves lots of deposits. Many Ford truck owners are just being cautious by not leaving the plugs in too long because we don't want to fork out 5000.00 dollars to have the heads replaced... Ford has been unwilling to back the people who do have problems so 80.00 dollars early to prevent this is just wise....



2000 Ford Mustang GT
2000 Ford Mustang Vert
2006 F-150 with shiney new plugs