Now I know this has come up before, but i was hoping someone had my tires and had some insight. I have Dunlop Radial Rover ATs P235/70R15 I know the gm spec is like 32psi,the tires have a max psi of 44. At 32 the seem really squishy so what is a good psi to be at that makes good tire contact and a good ride? I know the more the sides bow out the more they heat up and the less the middle of the tread hits.

 

You can use whatever you like between those two values. Any tire manufacturer will tell you to run what is on the door sticker to save them from any liability, but it is safe between those two values.

In the case of my Rainier, the values on the door are different front to rear with the front a few psi lower than the back. If I deviate from these (say put them the same), I get a weird vibration/binding while driving. For whatever reason, things are setup to run the staggered pressure. I have tried elevating it to reduce rolling resistance and found that when I raise the pressure, I have to increase the pressure difference F/R to get a smooth ride.

 

The trick I have always used to determine the correct pressure for my vehicles is to inflate the tires to the recommended pressure and then drive them a little ways (or put down a little dirt on the driveway and roll through it). After that I look to see where the dust/dirt comes to in relation to the breakover edge of the tire tread. The object is to have it end right at the breakover line and adjust the pressure up or down to achieve that. Then you know that you are getting maximum footprint without being over or under inflated.

 

the lable on my 4wd 95 Blazer 4door says 235 70 15 is 32psi front/rear. but i got 235 75 15 on my stock rims. is the recommed tire press still the 32psi or is it more since i got a different tire size?

 

Since this thread was from last year your best bet would have been to start your own thread. To answer your question I would say yes you should be fine still running 32 psi.

 

It depends on the load index of the tire. You need a load index chart. I have found some on the web as I had the same question as you. The stock 70 tires had a 102 load index @32 psi. If the 75's have a 105 index you can reduce psi to 29 since they can carry more weight at a given psi.