G-force
Cornering, braking and acceleration in g
What it is for
It helps you see whether you're using all the grip. If one corner pulls clearly fewer g than others like it, there's grip left there: you can brake later or carry more speed.
The diagram is drawn afresh every lap: try braking differently or change the setup, and you'll see straight away whether it grew.
Where you change it
Each change takes effect at once — there is no apply button.