Not sure what the recommended normal load tire pressures are for the cab. What does your fuel door sticker say? I know the cab is heavier, so I expect higher recommended pressures, but FWIW, I use 33/32 on my '19 coupe with the 19/20 wheels and PS4S tires. The PS4S ride noticeably more comfortable than the PSS it came with, but not sure how they compare to the Cup 2. The Cup 2 are meant for the track. Ride comfort is great for the most part, but our roads are not that bad. Higher pressures definitely get rougher and if I drive on a bad road it's not all that pleasant, but not too bad, either. Only potential issue with lower pressures is that you have less protection from potholes etc., so don't drive into one.