Tire pressure is the most basic handling adjustment, so an accurate tire pressure gauge is one of a racer's most important tools. Through experience, we've found that the CMC-spec Toyo Proxes RA-1 competition tire works best at a hot pressure of around 37 psi in the front and about 32-34 psi in the rear. Small adjustments can produce big changes in handling, so you'll need to work up to your own preferred settings. An old racer's rule of thumb is "add air, add grip." One of the single biggest handling improvements we made to our Mustang over the course of the season's testing was a 2-psi bump in rear tire pressure. We found that our SN-95 chassis's improved front geometry put less heat into the tires compared to our old Fox chassis, which required a 2-psi pump in static front-tire pressure to reach our target hot pressure of 37-38 psi.