When my tires reached their end of life at 40,000 miles, I was aghast. My Honda Civic had gone 80,000 miles on every set of tires I put on it - and I only paid $160 for a set of 4. So I determined I was getting 80,000 mile tires and bought some Cooper CS something or other tires (sorry to those for who actually know the models of their tires). Well, forget the dismay at the short life span of the tires - the new tires ate my gas mileage, which dropped from an average of 50 mpg to 45 mpg. I've had those tires for over 10,000 miles now, and the mileage has climbed to about 46 mpg. As I figure it, at $3 per gallon and 65,000 miles left on the tires - I am spending roughly $340 extra on gas between now and the end of life on these tires. This does not include the extra gas I've spent on the first 15,000 miles of the tires. So, I am trying to figure out if I should replace my new tires with the lightweight tires Toyota recommends that achieve the superior mileage? Or should I just hold out in hopes that the mileage will increase further as the tires wear and the friction lessens? Has anyone else gone through this? If so, what did you do?