Unusual tire wear

spotrot wrote:

zigzagrv wrote:
Generally speaking, over-inflation causes the center of the tire to wear and under-inflation the outside edges. The way to get the proper inflation is to weigh the axles, preferably the individual corners. This should get you in the ballpark of the proper tire pressures.

If both the inside and outside edges of the tire are worn, under-inflation is the problem. If just one edge is wearing, it is most likely an alignment problem.

All accurate info. What perplexes me (and may be of use to others) is that I weighed each wheel, and then used the charts for air pressure for that size tire. In fact I actually increased the air pressure over what the charts recommended but the tires still wore much faster on the outer treads. My guess: the chart was wrong or this particular tire construction makes the outer tread wear down prematurely

First, with regard to evenness of tire wear vs inflation pressure, there are forces at work that are stronger.

For example, steer tires tend to wear in the shoulders and drive tires tend to wear in the center. This effect is on the order of 3 times stronger than the effect inflation pressure has.

And lastly, the charts aren't wrong. Those charts are generic in nature. That is, they are published by a tire standardizing organization and are used by EVERY tire manufacturer when designing tires!

Plus, they are MINIMUMS, not recommendations. You should be inflating the tire MORE than what the actual weight/chart says. In fact most vehicle manufacturers add about 15% to the max load to get the specified inflation pressure - and the tire manufacturers know that, so they take that into account when designing tires. In theory, then, if you used the actual weights and the chart to set the tire pressures, the tires are going to wear like they are underinflated - and still, the effect wheel position has will be overwhelming.