<font color="blue"> Considering that ballast is used to increase weight/stability of the tractor and to prevent tipping/rolls; I would think that any fluids in the tires above the center of the wheel would "raise the center of gravity" of the tractor and "increase" the possibility of a rollover.
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Nope, just is not so. Would only work this way if the tractor was upside down and the wheels were on the top... /forums/images/graemlins/smile.gif
Reason is that any weight added to the tractor changes the center of gravity of the whole mass of the tractor, which now includes the added weight.
Almost without question one can state that the center of gravity of the tractor wil always be above the wheel centers.
The center of gravity of a balanced wheel is in the center of the wheel. When liquid is added to the wheel, since the tire is not completely filled, the center of gravity of the wheel is actually lowered.
The net affect is that adding fluid to tires essentially lowers the tractor's overall center of gravity a shade, and in no way can raise it.
So the net result is that filling tires with liquid or even totally filling them with a solid like foam fill, will always (at least in a practical world) result in a lower center of gravity and more stability.
Once issue that could be a concern though is sloshing in tires that are only half filled. At least in theory, if a condition would arise that caused the liquid in the half-filled tire to slosh to the top of the tire, then at this moment in time, the liquid being high in the tire, rather than on the bottom would cause a net increase in the tractor's center of gravity, and decrease stability, to some degree...
That's the way I see it working anyway... /forums/images/graemlins/smile.gif