I have a base C2 with standard suspension. I have played around with tire pressure front and rear and found the best handling "feel" to be when I use 28 psi front and 30 psi rear cold which translates into approximately 30 frt /33 rear when warm. I seem to be able to throw the car harder into the corners with a more planted feel at these pressures (mainly slower corners in the 40 mph - 70 mph range on my twisty daily commute). I also like the slightly "heavier" steering input I get with these pressures. Anyone think this pressure is too low? If so, what are risks other than premature tire wear?

 

Same car - base C2 with standard suspension. That is exactly the tire pressure I ran all summer as well on my summer tires.

My winter tires are running a bit higher (~ +2psi) than that now to accommodate for their softness / squishiness.

I hear that MPG goes down slightly with the lower pressure, but it is not significant. I consistantly got 27MPG on the highway, in line with estimates.

 

Just watch tire wear. If you are not eating the shoulders, dont worry.