A poorly aligned car will unevenly wear your tires at an alarming rate.
Wheel alignments are a service performed on your vehicle when you've replaced your tires. This can be done with the use of a number of high tech tools, like in the case of laser wheel alignments. The idea is that your wheels should be perfectly parallel to one another.
When your wheels are properly aligned, your vehicle will naturally perform better and drive more safely. In the long run, you'll notice that your tires wear more evenly and this will avoid unnecessary repairs or tire replacements in the future. The life of your tires will easily be extended with a proper wheel alignment and the savings and benefits will trickle down in many ways--improved gas mileage, fewer tire repairs and replacements, and safer operation of your vehicle.