CAM-S Corvette Tires & Pressure in SCCA Solo Discussion Posted February 13 Real old school method shown to me by some of the veteran Auto X guys. Get yourself a good tire crayon and mark your sidewall near the wear bar triangle. Your goal is to get the crayon mark to wear down to the top of the triangle. Start your tire pressure around 30 psi or so and adjust accordingly. Not an exact science but gets you in the ballpark. You don't need to wait until the next event, try it during your next Z06 "therapy session".