I ran over a nail and flattened my tire. My mechanic was able to plug it for a couple of dollars and it holds air ok but is it still safe to drive around spiritly or should I buy a new one? It has alot of tread life left on it so it would be a shame to have to get a new one.

 

You should be fine.

 

Perfectly fine. I've had it done a number of times. As long as it didn't puncture the sidewall (in which case they generally can't and don't plug it), the tire fidelity is fine.