For some reason, when we first recorded our Xbox One X footage of GRIP the other day, we experienced what was without a doubt a 30 fps framerate. Now we don't know if it was a bug (of the game or the console itself) or if the game was updated after our recording session, but clearly its framerate is now unlocked and apart from the starting GRID where the number of frames may drop a little, it seems to be pretty smooth. Here's a bunch of new gameplay video that we recorded without the grainy filter and while using the most powerful car engine category.
Update: 2 FPS Analysis videos added. They confirm what we were saying just above.