If a tire loses all or most of its air pressure, it must be removed from the wheel for a complete internal inspection to be sure it's not damaged. Tires that are run even short distances while flat are often damaged beyond repair. Most punctures, nail holes, or cuts up to 1/4 inch -- confined to the tread -- may be satisfactorily repaired by trained personnel using industry-approved methods. Don't repair tires with tread punctures larger than 1/4 inch, or any sidewall puncture. Also, never repair tires which are worn below 2/32” tread depth. Your best bet is to make sure your spare tire is always ready to do the job. Check it regularly for proper air pressure and be sure that it is in good shape. If your car is equipped with one of the several types of temporary spares, be sure to check the spare tire's sidewall for the correct inflation pressure, speed, and mileage limitations. See your dealer for expert tire repair.