Here at our local small track, we race on Sat. night. Its no big deal during the summer months, but as we get closer to the colder months those tire warmers really come in handy. The people who had the warmers got huge early race leads during the cold nights. Leads that usually couldn't be made up by people who didn't have them.
You can always run really soft tire compounds during the cold weather and they will hook up. But having the warmers lets you avoid those high wear compounds and still lets you get traction.
But, unless you race year round where its cold, you'll only get to use them for about one-two months out of an average season.
Still, there something good to have in you pit bag.
TLR 22...Tamiya F104...