The biggest problem here is that each manufacturers tyre will respond better to different pressures and driver preference plays a part here. I find anything below 32PSI on the front on my 195, 50's just makes the steering soggy, bloody heavy at low speed and I personally like the rears to be a bit higher in pressure to balance the car out and sod the wear (they dont wear much on the back whatever pressures you run anyway). Best option for you is to set the rears at one pressure (I run 36-38psi but 28-32 is probably more realistic from a wear and grip point of view) and experiment with the front pressures till you find a setup your happy with, once you have a pressure your happy with on the front, just keep an eye on their wear patterns to make sure they are wearing evenly. The rears arent really doing much so their pressures arent as important to setup unless you want it to slide a bit when your pressing on to help the front end out.
