What is the proper tire inflation for my car for performance driving?

For performance driving things are a bit differently from normal inflation pressures because there the aim is to reduce tire flex and to adjust the over all handling characteristics of the car. Generally, in an autocross or a ralley you will be running at a much higher pressure than normal. One of the old tests is to put chalk marks on the side of the tires, go around the track, and check how much the tire has "rolled" under (i.e., how much flex caused you to scuff the sides of the tires).Note -- this only works on "street" tires. The sidewalls on competition tires are just too stiff for the chalk technique to work -- you need to use a pyrometer and a stopwatch. where@maple.circa.ufl.edu on chalk: Typically speaking, If you run street tires when you autoX, you'll want to bump the pressures up from what you run on the street, but ONLY for the time you're racing. When your racing day is done, bleed the pressures back down to reasonable street pressures, and drive home. Many of the ...  more