Every once in a while you will get a flat tire: it’s an inevitable part of driving. 95% of the time the cause is a nail or screw that was lying on the road and made its way into your tire. If you are lucky the offending object will have lodged itself into the center of the tread, you notice it quickly and have it repaired.
Flat repairs are a frequent service at most auto service and tire shops. There are several ways to repair a flat, and there is a right way and a wrong way.
The wrong way is to use a plug. A plug is a rubberized ‘string’ that can be inserted into the hole left by the nail or screw. The repair procedure is simple and cheap which explains its attractiveness: simply pull out the nail or screw, insert the plug, trim off the excess with a knife, fill the tire with air and then drive away.
The very simplicity of this repair is the major thing that makes it wrong. In order to do a proper flat repair the tire must be taken off the rim and inspected. Many times we find that the nail has damaged the tire’s sidewall or that the vehicle was driven for an extended time with low pressure before seeking out the repair. This leads to sidewall damage. By simply plugging a tire and continuing to drive you could be sitting on a potential time bomb.
So what is a proper flat repair? If all looks good from the inepection then a patch or a combination patch/plug can be installed, the tire remounted and reinstalled on the car. This is a trouble free, safe repair and is the type approved by tire manufacturers the world over.
Unfortunately there are times when we find tires that can’t be repaired even before taking them off the rim. This occurs because the sharp object has entered the sidewall or is in the tread but too close to the sidewall to repair. In this case replacing the tire is the only option and frequently this leads to replacing more that just the damaged tire. It is critical on most modern cars to keep tire treads depths very close to the other tires. Tread match is also critical. With antilock brakes and all wheel drive systems consistent tires are that much more critical.
Is there ever a good time to plug a tire? The only instance that I can think of is if you are on an off road trip and are miles from proper tire repair. Of course you will need your own plug kit and an air compressor, so this is a well preplanned and thought out strategy. Otherwise always insist on having a proper flat repair for your safety and peace of mind.