We've already seen that Project CARS 2 doesn't split work across host processing resources particularly evenly. One of our Ryzen CPU's cores is overloaded while the others, physical and logical alike, don't do as much. Let's see what happens when we toy with core and thread count. For this experiment, we standardize on a single graphics card: AMD's Radeon RX 580.
Slightly Mad Studios recommends a quad-core processor at least, and it appears the company's guidance is justified. Getting even more specific, you want four physical cores to avoid large frame time variance spikes. With only two cores, the frame rate drops noticeably.