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I still am missing the point of interest in the "heaviest 55 hp tractor"
Help me out here, please </font>
I can't help you out because I see it from the same general perspective you see it from. I've been a long time advocate of the point of view that in the world of homeowner type CUTs that the entire concept of Weight = Traction is just a bunch overblown hooey for most people (not all, but most). Now I also state that some applications require weight but those are more specialty applications. For the most part, anything defined as a CUT is probably better off being a bit on the light side of the spectrum provided it has the frame strength that will allow it to be ballasted up in weight to achieve proper balance for specific tasks.
I can point to examples of heavier tractors having slightly less lift capacity than lighter tractors and even the manufacturers of the heavy tractors recommend ballast boxes, filled tires, etc when using FELs. So I believe that balance is the more important in the world of CUTs than overall weight. Again, I believe that sometimes there is no substitute for raw weight, but for most users and most applications, the practical advantage of excess weight is minimal and the disadvantages are often apparent in the form ruts, higher fuel consumption (although that is a minor issue), and excessive bulk.