Our historically underpowered, mildly understeering, ~3100 lb RWD B/C-class car runs the Azenis RT-615K+ in 225-45-17. We buy two tires every race, put them on the rear, and cycle the 1-race rears to the front. If we shelled out for practice on Friday, we generally do this after practice.
Assuming we run the whole race with minimal issues, the car definitely starts to feel a little plow-y toward the end of Sunday. The fronts we take off are usually bald on the outside with a tiny bit of tread left on the inside, but no cords visible. The new rears usually end the race at 80%.
(All of the above subject to change if we get this turbo situation figured out.)