I just had a tire blowout on a Hertz rental. I drove on the doughnut to the nearest Hertz location. They switched cars and warned me that I would be liable for the cost of replacing the tire when I turned it in. He said that "service" items like tires are the responsibility of the renter. Service items on a vehicle suggest to me windshield wiper blades, fluids and light bulbs.
He told me it was just as if I had had a blowout on my personal car. The rental was a new car. I inquired if the warrenty would cover a blowout on a new tire. He just smiled.