There have been times when the technicians at Don's Automotive and Truck Service have found spark plugs seized in the cylinder heads of some of our Lisbon Falls 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 Don's Automotive and Truck Service. There have been rare occasions when Don's Automotive and Truck Service has needed to remove cylinder heads just to get the spark plugs removed. Don's Automotive and Truck Service suggests that in order for our customers in the Lisbon Falls are to maintain peak performance for their vehicles, that their spark plugs should not be run longer than 30,000 miles. Don's Automotive and Truck Service suggest that consumers should take those 100,000 mile spark plug marketing claims of manufacturers with a grain of salt.