I'm clueless on this one now I guess, from first post, I too was under the impression OP had E rated tires and 6,000# rated axles, thus the reason I recommended Michelin XPS RIBS...Now I'm understanding, possibly, that his axle ratings are even more than my 7,000# rated axles which I have GY G614's mounted on. My 5er has a GVW of 16,950#.
To the OP, what is the GVW of your 5er? Has to be a placard on the unit somewhere, should also be one stating OEM tires used....either outside or on inside....Have you looked to see if this information is posted somewhere on your 5er? It would really help us answer some of your most pertinent questions.