Here is how I came up with the approx. pressure to run in my tires. Went to the tire web site and looked up my tire, then roughly calculated the weight on the tires and started high in pressure and have been working them down a pound at a time.
Here is a link to the firestone all traction utility tire.<A target="_blank" HREF=http://www.firestoneag.com/tiredata/ag/rear_tractor/rtr_atu.asp>http://www.firestoneag.com/tiredata/ag/rear_tractor/rtr_atu.asp</A>
Gordon