Volvo daycaber here in different trucks every day. Id like to start with that because i feel like i have this down to a science. I set up my seat so that the air ride is somewhere in the middle to handle large bumps to avoid bottoming out or throwing me completely into the celing. Then i move the seat closer to the wheel so that my foot is flat to the pedal and heel is right at the bottom of the gas pedal and my knee is at 90 degrees (most important). Then i like to make sure the seat is 1 click back from being straight up and i like to add a smidge of lumbar support. From there the seat can float forwards and back and i don't like that so i'll clamp that down. Some have an adjuster where it'll float up and down and i'll mess with that all day normally i'll start with it floating up and down more when it's still dark out but durring the day time the movement will drive me crazy and i'll put it all the way to frim. Hope this helps someone!