Tom
I have that same piece of literature in front of me....and referred to it in the above text too. I am not too sure why they list those dimensions the way they do. It could be with using the minimum inside dimensions for row-crops or other purposes. But then they list the O.S. width without saying its the max (I think its the max anyway...with R1 tires and 8 position wheels). The literature is definitely confusing IMO.
Long and short of it.....The 3x20 is a good tractor for use "generally" with five to six foot implements on the back and with loader buckets from five to six feet wide. I think this is true of competitive model tractors. For this reason, the manufacturer has to keep the tire width to accommodate those implement widths...or.... your not going to be able to mow up close to fences and buildings or you may drive over crops etc, etc.
So....if brand x has a five inch wider (than 60") tire width, than the five foot mower width to go with said tractor.....then what favor has he provided you....if you want to use five foot implements? (Keep in mind five foot implements are cheaper, lighter, require less HP and are easier to maneuver...yadda, yadda....and some of us view this as a positive.)
Again.....most of the COMPACT tractors are set up to operate five to six foot implements (yes there are exceptions). So....after you figure out your implement preference.....then start looking at appropriate tractors to operate 'em. IMO
One thing about the 3x20 series tractors.....the 3320 is great with the five foot implements....and the 3720 may be better with the six foot implements...both due to the HP they offer. (and the 3520 is in between somewhere) The tractor may not be as stable with the heavier six foot implements as with the fivers?....or with a cab? (you be the judge)
I think many operators want stability. Many here load the tires to gain extra stability and to properly
ballast the tractor for loader use. Some install wheel spacers to gain extra width and greater stability (again....generally, when they use the wider implements for the tractor size)
I think with these facts in mind.....tractor "width" will be viewed in the proper perspective. :thumbsup: