Tire rotation refers to the periodic moving of each tire's place on your car. Every 5,000 miles or as advised by the car's manufacturer, you should rotate your tires. For many of you, that would be when you change the oil in your car.

You should rotate your tires on a regular basis so that you have a chance to visually check them for damage, check the air pressure, have them rebalanced if you hear any vibrations, and measure the tread depth.

The alignment of your wheels can become out of whack with regular driving, though it can occasionally be subtle. As a result, your car is harder to drive, gets worse gas mileage, and wears out your tires more quickly. For better traction on the road, an alignment involves bringing the angles of your car's wheels back to their original specifications.

Toe wear or, in more severe circumstances, camber wear, which is excessive wear on the tire's inner or outer edges, is a sign that the wheels may not be aligned properly.

The width of the appropriate tires for your vehicle, in millimeters, is the first number to appear in your tire size information: P225/70R16 91S.

The dimension from one sidewall to the next is always referred to as the tire width. Therefore, a tire marked "P225" is for a passenger car and has a nominal width of 225 millimeters.

The following number you see after the slash represents the aspect ratio of the tire, which effectively indicates how tall the profile of your tire is: P225/70R16 91S. Deliveries of aspect ratios are done in percentages. The aspect ratio is calculated by dividing the tire's height off the rim by its width by tire manufacturers. When a tire's aspect ratio is 70, its height is equal to its width in proportion.

The next number is the diameter code, in inches, of the rim onto which the tire can be mounted. For example, a tire with the P225/70R16 91S would fit a rim with a 16-inch diameter.