There have been times when the technicians at My Transmission & Auto Care Experts have found spark plugs seized in the cylinder heads of some of our Montgomery area customers' vehicles with as little as 60,000 miles on them. The removal of these seized plugs can result in hours of labor by our technicians at My Transmission & Auto Care Experts. There have been rare occasions when My Transmission & Auto Care Experts has needed to remove cylinder heads just to get the spark plugs removed. My Transmission & Auto Care Experts suggests that in order for our customers in the Montgomery are to maintain peak performance for their vehicles, that their spark plugs should not be run longer than 30,000 miles. My Transmission & Auto Care Experts suggest that consumers should take those 100,000 mile spark plug marketing claims of manufacturers with a grain of salt.