Got the new tire put on the Gravity 23" wheel today by a Discount Tire mobile van. The guy has worked on Airs before but not a Gravity. However, he already knew how to put the car into jack mode, something I had forgotten needed to be done. The only hiccough was that the van did not have the equipment to do a roll force balance as I had been told it would. He said that he had the same balancing machine they have in their shop for roll force balancing, but there is not room in the van for the force application mechanism. Overall, though, it was a very smooth tire change and something I'm relieved to know I can get done at home in the future.
He also checked the tire tread on our first Gravity and approved it for a road hazard tire warranty even though it has 3650 miles on it. So we're buying the warranty for that car, too, given all the construction around here.
Also, while the tire was off the wheel, we weighed the 23" Gravity wheel. I was disappointed to find it was not forged as our 21" Air Dream wheels are, and it came in at a hefty 40.6 pounds. (The tire weighed 37.2 pounds.)