Recently purchased my car from an area of lower altitude. Upon taking it home, I felt the tires was very stiff and responsive, although it did feel at times that the back would kick out a little on sharp turns. It dawned on me that taking it to a mile high increased the pressure. Checked and all were at 36 psi cold. So I dropped the stock tires to the recommended 32 psi cold and now it feels a bit *flabby* to me (a bit more sway). Is the recommended psi optimal or are ppl running slightly higher or lower tire pressure? Forgive me if this has been covered but my search for *tire pressure* produced no threads that answered my question.

 

From what I have gleaned most that are not running the factory spec are running higher pressures. Some are varying the pressure front to back, usually with a higher pressure in the front to promote some understeer. The theory being-higher pressure = slightly less grip on the fronts, therefore understeer.

My experience has been mostly running 37 psi front and 35 psi rear, both at the track and on the street. This has done three things for me:
1. Better gas mileage.
2. Provided understeer.
3. Increased tread life (I think).

I'm now trying 35-36 psi all-around on the street but I don't have any track time yet at these pressures. Note that higher tire pressures increase ride harshness, but hey this is a sports car and I'm really into ride harshness.

 

I would really suggest you do some testing with your car and your tire pressure gauge. The theory presented about harder pressures in the front may not give you the stable backend as indicated. Go play with this yourself and make your own conclusion.

I run 32psi in the front and 35psi in the back. The backend of the car is WAY more planted and less prone to oversteer. The front and the rear tires are different sizes and under very different loads. Why people seem to believe that they should act exactly like each other with the same number of pounds in them is beyond me. All I know is my car is handles better with a few extra pounds in the back and I have several engineering/race friends who can explain in nauseating detail as to why higher in the back is a great way to dial out some of the oversteer in this particular car.

I have debated this issue until I'm purple in the face and will not keystroke any more.

 

Thanks for the responses. I agree there's probably is no right or wrong answer and it's a matter of load, road surface, driving style and preferred *feel*. Revealing my ignorance, would someone explain the definitions of oversteer and understeer. I'm guessing oversteer would be the condition where the car may surprise you as far as how fast it bites and understeer, of course, would be the opposite where one would feel like they have to hit the steering more than necessary to get a good tracking feel. Correct me if wrong. The balance I'm trying to dial back in (that I feel I have lost when dropping to 32 all around) is the ability to carve (that *on rails* feeling) but without the rear-end volitility/sway. Under the previous 36psi all around, when I felt the rear end *hop* for that split second, it concerned me that I was nearing the limit of control and it might kick out more drastically and cause a spin. Although I haven't tested the new 32psi all around extensively yet, it does feel initially that the car will hold the road better but the *sway* it's added (oversteer?) is perhaps worse since it means continually compensating throughout a turn rather than simply turning the wheel and letting it smoothly ride through it (assuming I've entered the corner at the correct arc to begin with). Thanks again, for the benefit of your experiences.