I now have mine set pretty good, running 30x9.5's, stock(and probably original) struts, no-name crown vic shocks, I have 20psi in the front and about 17psi in the rear. I dropped them to 13/14 & 15psi last weekend, but found it sluggish on take-off. Putting them to 25psi was way too hard for me. I'll be leaving them the way they are now for a while. It's really a trial and error thing depending on your area's road conditions, and your preference.