If the tire was run on the car flat for much distance, it usually rips the cords inside the tire loose and destroys it. If anyone has put "fix a flat" liquid that is bought at convenience stores or gas stations in the tire they may not even mess with it or charge more. If it is just a nail or screw that put the hole in the tread it takes very little time for them to break the tire down from the rim and buff around the hole to help the glue stick, then put a patch on. If the hole is in the sidewall they may not fix it. If the tread is worn down a lot then it is time for new tires. After they wear down a lot the flats start happening.

Repairs of all tires must be of the combined plug and inside patch type. A tire should be removed from the rim and checked before repairs are done. Any tire repair done without removing the tire from the rim is improper. Take note that, any improperly repaired tire can fail suddenly at a later date. Your will need replacement if the tire is worn out. More information on tires go to http://4wheelonline.com/Mickey_Thompson_Tires.1724

Sources: http://4wheelonline.com/Mickey_Thompson_Tires.1724