Alex's Automotive Performance guide

When rotating your tires, it is also important to measure their tread depth to help determine if your vehicle has an alignment issue. You may find that when the edge of a tire wears differently than another it can point to camber.

• Negative camber is wear on the inside edge of a tire and is pretty common on performance-oriented vehicles. It occurs when the top of the tire tilts inward toward the center of the vehicle. When a vehicle is lowered beyond stock ride height, additional camber is added. This can begin to become excessive causing consistently quicker wear on the inside edge.
• Positive camber causes more wear on the outside edge of a tire because the top of the tires lean away from the center of the vehicle. Read "Alignment" to gain a better understanding of camber and how it can affect your vehicle.
 

In addition, one of the most critical alignment settings relative to tire wear is the vehicle's toe. Toe angle identifies the exact direction the tires are pointed compared to the centerline of the vehicle when viewed from directly above. A toe setting that is just a little off can make a huge difference in the wear. An axle is said to have positive toe-in when imaginary lines running through the centerlines of the tires intersect in front of the vehicle and have negative toe-out when they diverge.

• Toe-out is used to get a vehicle to respond quicker to steering and cornering response.
• Toe-in is used to keep a vehicle tracking in a straight line.

Take a look at the diagram below to get a visual understanding of toe-in and toe-out:



You can keep your tires quiet with good monitoring and find a good rotation schedule based on wear not mileage. I will rotate my tires once I begin to see a deviation of 1/32" difference in tread wear. View the benefits and instructions on proper tire rotation in "Tire Rotation Instructions." Once the tires have been rotated, be sure to check your tire's pressure. I use the Intercomp Deluxe Air Pressure Gauge as it makes pressure adjustments easy!

Running non-standard tire pressures on all my vehicles, my rule of thumb is to never keep the tires below the manufacturer's recommended pressure. This allows me to get the tires to wear as evenly as possible. Good notes to remember when checking your air pressure are:

• Wearing in the middle of the tread, you need to lower pressures.
• Wearing on the edges of the tire, you need to raise pressures.
• A tire loses on average 1 pound per month during normal driving.
• For every 10 degrees Fahrenheit temperature change, expect to see a loss of 1 pound of pressure in colder temperatures.
• Conversely, pressure will rise roughly 1 pound for every 10 degrees Fahrenheit increase in ambient air temperature.

This of course should only been done on a solid alignment. Otherwise you may be compensating for wear due to misalignment.