Comparing lap times with stock cars against real life data, you will typically find that something like a hot 200tw (Yokohama A052, Bridgestone re71rs, CR1, etc) runs lap times between a CS and SH. Most trackday tyres, 100tw, etc are a little faster between SH and SM(though it is worth noting some of the 200tw are just as fast on track as the 100s, for a lap or two...) and something like a Hooosier A/R7 turns laps a tick slower than the same car on SS tyres in the game.
There is plenty of data on stock cars that are rendered in the game. Between press testing the BRZ and data from 86cup, there are a lot of lap times and even telemetry available on these cars at Laguna and Willow, for example. It's been a while since I've tested them, and the physics are constantly updated, so perhaps it's worth another look.
It is also worth mention that lap times alone are only part of the picture when comparing to specific real life tyre models. Even in real life, tyres that turn similar lap times often do so very differently. Some tyres have better longitudinal grip, others lateral. Sometimes one tyre is better putting power down and braking, but another has more lateral grip and higher corner speeds; and they can run the same times on the same car but you have to drive them differently. When I had tested previously, I used a combination of known car lap times and data from 86Cup, which provided not only lap times but also telemetry including geographical line and speeds at all points on the track. So it was easy to compare straightaway max speeds, braking points, cornering minimum speeds and minimum speed points, etc. From there, you can gain a better picture of how each tyre behaves, and compare that with the data you obtain in the same car on various tyres in game. Again, perhaps time to revisit.
