help with my drive tire choice

I never run door jam pressure, cause the specs there show a low pro tire & I do not have low pro tires.

 

I e-mailed michelin & asked about the tire pressure. waiting for a response. when I had the low pro's my top end was 68 m.p.h & that was if there were no headwind & on a flat. so the bigger tire gave me a lil more top end with less r.p.m's. I always thought if you have a tire mounted on anything, whether car, truck or wheelbarrow, what is says on the tire is what should be followed.same as the 105 p.s.i mark, why would I run 85 p.s.i. when it says 105? figured maybe cause of the load rating & composition of the tire , it needs to be at the specified pressure? I do not know. maybe I need to put 105 in there. will see what the experts say at michelin. I may try to mark the tires. wonder if a chalk mark across would do? I need to find out quick. I do not want to ruin a new set of tires.

 

I marked the tires. it appears the marks wear off in the center first. as far as inside or outside it wore both off evenly until gone. looking at the design of the tires the ends look like they taper off on a slant, making less hard contact with the ground than the center of tire. tried once with spray pain & once with a marker loaded. I think I may need more test to be sure.

 

trying to figure out chart. I am always at 80,000 lbs. for the most part. I just am not sure how to read for my 11r22.5 tire weight? with 80,000 lbs total & 34,000 on both drives divided by 2 = 17,000 lbs per axle. according to the chart 18,320 lbs which is the min weight they list p.s.i. should be 75. I know I am miss reading something. really hate to admit my stupidity. but I still don't know the correct p.s.i. looking at the chart.