Ask technicians and engineers about manually tuning PIDs. Their responses usually fall into one of the three different groups: 1) Some who will say it’s a “dark art” and won’t stray from an OEM’s default parameters, 2) The majority who will describe approaches that are based on seemingly random trial-and-error, and 3) Very few who will have truly figured it out. My career has thankfully allowed me to rub shoulders with enough practitioners from that last group and with their guidance I’ve cultivated a list of tuning tips that have served me well.