I've been running my BFG's K02's in 275 70 17 (load range E) for the past two months. Initially they were filled with 32 psi from Discount Tire. To me they looked flat when sitting so I bumped it up to 42. It seemed to help but notice outside edges on front tires were starting to wear. I bumped it up to 50 today. With these being load range E tires I read you have to run higher PSI. Is that true? What is the proper psi for these?