I took my 2011 GMC Acadia in for routine maintenance at 22,500 miles. The dealer suggested I have the alignment checked (no charge) and I agreed. Sure enough, he reported that the toeing in the left wheel was off .25 of a degree, and the right was off about .19 of a degree. All the other measurements were OK. He wanted $100 to fix this. I declined for the time but would like to know if such a small deviation is important for safety and tire wear. Are there certain benchmarks to use in determining whether or not the wheels should be adjusted?