I used to before I got a direct drive trainer. Sure, I had plenty of old tires, but my trainer used to shred up cheap tires, leaving bits of rubber and dust everywhere. The trainer tire eliminated that residue, was quieter and gripped better. I also live in Wisconsin where I'm on the trainer 5 months of a year. I think some of the better trainers are more forgiving on tires as the contact surface is larger. I had a cheap $100 Nashbar fluid.