i5-4440, 8 GB, RX-580 What graphic (and not only) settings should be reduced primarily to increase FPS?
Anything to do with mirrors, shading, shadows, time of day, number of cars visible, track animations.
Number of cars can make a huge difference right off the bat and may allow you to keep higher settings for some of the eye candy. As Vale mentioned all of these can eat up resources but some simple changes made can recapture FPS without affecting your experience too much. Time of day is a great example, I run all my races at noon as the sun is causing the least amount of shadows of trees but does keep the shadows from the cars, which just look goofy without them. These two alone provided a big enough increase for me that all other settings were left at high. Good Luck @Kabanito and race on.