Pretty much every Loaded trailer, for example I was pulling the lizard triaxle dump trailer when empty handles absolutely perfect gets up to speed no problem pulls up hill no issue only looses a little speed. However when the trailer is loaded with 73,000L of stone it’s like I’m pulling against a brick wall. I’ve adjusted the air ride up and down, moved the hitch forward and back and it’s the same story. It’s the same way when using a lowboy and hauling any of FDRs excavators or FSMiners mid size dozers an excavators (D5, 349, etc).