Board Thread:General Discussion/@comment-27798333-20170108235759/@comment-29898480-20170207230336

OK, that was interesting to look into. More racing occurs on non-DOT than I thought, but in SCCA and NASA a large majority of the cars raced are required to run DOT. Those that aren't requried are the "wings and things" classes (Formula cars and prototypes), the silhouette cars (Trans AM & GT-X, though some GT2s require DOT) and production classes (read: old guys in old cars mostly). These days those are the lowest participation classes at the regional/divisional level, though they do better at the national/majors level. The biggest participation non-DOT class is Formula Vee.

All the most highly populated classes (with the exception of Formula Vee) run DOT: SM, SRF, and all the Touring (including Super) and Improved Touring classes. That's gonna include ~75% of the cars at a divisional/regional SCCA event in New England. Also running DOT are American Sedan and the newer spec classes (E46, Mustang, MX-5), but those are all low participation.

It looks like you can crudely break it down like this: if the car was born on an assembly line, it runs DOT. If it was fabbed in a race shop, it doesn't. SRF (spec racer ford) is the big exception with its spec DOT Hoosier tire. I didn't go through NASA but a quick scan showed a similar pattern.

Looking at that through the eyes of RR3, almost every car through Expert does or would class into Improved Touring, Touring, or Super Touring, with some other stuff thrown in. In Master the GT-3 spec and some Formula cars are showing up, but there are still a bunch or ST and T1 level cars. Elite gets more into the purpose built race cars and un-raceable (in the real world) hypercars plus some that look like ST class cars. And Legend even more so then Elite.

I have no idea how what goes on outside the US.