Estimate on PSI for auto-x
 

I searched and I only found responses for lighter cars...obviously, my car weighs quite a bit. I'm running worn down Potenza S-03's 215/55/16 at the track, how many PSI should I go with? I'm thinking like 37.5. And how much of a difference will having more or less PSI in the back make? Thanks in advance guys.

Chris

Use some chalk on the edges of the tires. You should scuff the chalk not past the shoulders of the tire.

I would start higher personally since I Know the sidewalls on the S03s are softer than the Azenis and I run 38f/43r. I would go with 41f/43r to start.

I think the max PSI on the S-03's is 39.

When doing autocross/track competition things with DOT rated tires, don't pay a huge amount of attention to the max PSI. That pressure is the maximum rated pressure for the maximum load on the tires for highway driving. For track events you're usually varying your speed often, and a slightly over-inflated tire will generate less heat while rolling, just make sure not to drastically over-inflate, as this will cause the center of the tread section to hold more heat than the edges, which isn't good. Besides that, for most track sessions you remove all the unneeded items from your car and run about 20 min. max, so you should still be fine, just tune the pressure to use the full width of the tire without rolling over in the turn, and drop the pressure back down as soon as your done to avoid stretching the tire too much.

I think I had some coherent thoughts in there...

Thanks for the help guys. 40.5/42.0 worked extremely well :thumbup: