Interesting observation. Obviously the weight of the tractor at each tire divided by the sq inches on the ground is the pressure on the ground in psi. To a large extent this is dependent on the pressure in the tire. I believe mine show 18 psi rear and 34 psi front with a tractor weight of 8000#.
From Firestones Web Page: The footprint at no penetration/3 in penetration:
16.9x30 R1 Ag Tread 3750#@18psi 216 sq in/540 sq in
9.5x24 R1 Ag Tread 1870@30psi 79 sq in/245 sq in
Assume reasonably equal loading with loader and all wheels filled with
ballast. The loading would be about 1/2 of this without a loader and without ballast.
13.55 psi loading on the grass with no penetration
5.0955 psi loading on the dirt with 3 in penetration
That seems like very little ground loading with an 8000# tractor. It would be interesting to see what it would be at lower inflation pressure but I could not find that data.
I imagine that turfs will come in about the lower value of 5 psi and R4 tread will be somewhere between 5 and 13 psi. Wonder if this loading is pretty constant with different size Kubotas?
Tell JimBinMI that I used EXCEL to do the calculations, but he needs to come over and check them. /w3tcompact/icons/smile.gif