I drive the car about 800 miles a week - all freeway. The first rim cracked at around 65,000 miles (left rear). The second at 108,000 miles (right front). The rims are the "12 hole steel" type. They both cracked in the center section, near but not on one of the 12 holes. Neither rim was cracked on the outer section (the part the tire mounts to) or at the axle stud holes. The car has never been in an accident, has never been raced, and has all stock parts.
The original rim was a 14" x 5". When I purchased the second rim from the dealer, I noticed it was 14" x 5.5". I mentioned it to the parts guy and he said "this is the re-designed rim, much better than the old 14 x 5 style". I asked why the new design and he didn't know. I asked what problems they had with the original design, and he didn't know that either. I checked the first replacement I had to buy - it was also a 14" x 5.5".
I realize cracked rims are very uncommon. It just seems weird that Ford "re-designed" the rim and my keep cracking - but no one elses do.
Thanks to everyone who replied! I'm really enjoying this site and look forward to offering any information I can to other Contour owners.
