I use 60 (FOV talk has been beaten to death). Except, in the MRT, at 60 you don't see ANY of the car, LOL. I have to see at least something to get feedback and the gauges as well, so I just use the 5/6 keys to move it back. Problem with that is, I'm use to the view at 60 and more than that, I end up braking too much because I can't drive with the view perspective all stretched forwards like that. I end up braking, then needing throttle again to reach the corner, LOL.
And yes, for the original post, 90 is default.