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