Appreciate the feedback. The wheels are aluminum. My current Marathon's are original and while they were kept covered in sun when possible, they are showing some small sidewall cracks this year and got to go. The only reason I am considering 215 D range is that is what Costco carries (I did not see where they sell the 205 C range) and its a good price. They will ship the tires to the nearest store and will mount them for me.