anyone got an idea about this?

[firemen122]

While I didn't check the math, just remember that you generally don't fill the tire to capacity with fluid. Rather you generally fill to just above the axle - allowing for some amount of air to remain in the tire.
Mike

Down here in Fl. everyone I know fills tires full....

 

[Midsouth]

The way mine was filled was with the valve stem at about 11 o'clock. That leaves just a little air in the tire to make it ride better.

 

[RWolf]

Rolling--I'm running the 14.9's as I wanted more than the standard tire but I wasn't sure about the 16.9's. My 5103 is a 2wd also because I figured with pretty much level ground and that I really don't expect to be using ground engaging jobs on a regular basis.