THE Holden IRS is a bit of a compromise and tyre wear was a particular problem. The wear is caused by the toe-change that occurs as the wheel moves up and down as the suspension moves from bump to rebound. It's worse if the suspension is lowered for any reason, either by changing springs and shocks, being loaded or towing. Some suspension specialists have developed kits to fix the problem. Talk to Pedders, K-Mac or other specialist outlets.