Click and Clack Talk Cars

Tom and Ray Magliozzi
Friday May 17, 2002

Dear Tom and Ray: 

Whenever I find a pesky nail in my tire, I take it to a service station or tire store and have them “plug” it. A friend of mine told me I should have an internal “patch” installed instead, because a plug will weaken the internal bands within the fabric of the tire. Which is better, plugging or patching?  


- Richard 


TOM: My brother was asking the same thing the other day. But he was talking about his own bald spot. 

RAY: The safest thing is to do both, Richard. If you ask anyone involved in auto safety, they’ll tell you that a combination patch/plug is the best way to go, and our lawyers have told us that we agree. 

TOM: Here’s how a plug works: You remove the nail or sharp object, and then you make the hole bigger -- usually 1/4 inch or so. You do this to make the hole the right size for the plug and to create a uniform surface for the plug to adhere to. Then you force the plug into that hole, along with the appropriate cement, and you’re done. 

RAY: Safety advocates say that this is not a perfect solution -- although, to be fair, people have been successfully plugging tires since Ben Hur was running over Coliseum debris in his chariot. And the great advantage of a plug is that it costs about five bucks. 

TOM: A safer solution involves adding an internal patch to the plug. To install a patch, you have to remove the tire from the rim and cement a rubber patch over the hole on the inside of the tire. That pretty much ensures that no air is going to leak out. But now you’ve turned a $5 repair into a $25 repair. 

RAY: So what you do probably depends on several factors. One is the size and type of the hole. A small nail that went straight through the tread is a better candidate for a plug than a jagged rock you ran over. 

TOM: The age of your tires also makes a difference. If you have less than 50 percent of your tread remaining, or if your tires are more than three years old, you should either patch/plug or consider just buying new tires. 

RAY: The quality of your tires can also affect your decision. If you just bought four $150 Michelins, you’d be more likely to “fix them right” with a patch/plug combination than throw them out or just plug them. 

TOM: And the type of driving you do can make a difference. If you do a lot of high-speed driving or you live in a hot-weather area, you’d be wise to patch/plug or simply replace a damaged tire. 

RAY: We should mention that all of these repairs are only for tread punctures. Under no circumstances should you ever try to fix a damaged sidewall. It won’t work, and it’s dangerous to attempt it. 

TOM: In your case, Richard, since running over nails seems to be a common occurrence, it might make more economic sense to use plugs. As for my brother, I’m recommending that he skip the plugs and go right to the “spray-on hair in a can.”