Just gave it a go. I lied
It was anywhere from lowish 40's when there were a grid full of cars and smoke ahead of me to 60fps with nothing but road ahead. Strange that I couldn't tell before, I'm usually quite in tune with FPS.
I'll try it with a lower resolution later to see if it makes much of a difference.
Thanks for checking pal. That's exactly what I got at a lower res!
I wonder if the fps is capped somehow?