I have a 190e 2.3 16v. It has 17 inch wheels and Potenza 250/45/17 tyres. I noticed that the outside edge of the drivers side front tyre is going bald all the way round. The width of the wear is about one and a quarter inches. All the other tyres are o.k. I have had the tracking checked and they said it was o.k. What could be the problem ?? Thanks in advance for any help.