This is an interesting comment that I don't quite know how to respond too. I probably "really use" my tractor more than most people on this forum. While I don't plow or cultivate most of the spring and summer I steadily use most of the horse power available at the pto. While I do live in a flat area most of my work in summer involves irrigation ditches which are far steeper than most road ditches. Any sort of wheel weights would work against me and I certainly don't need it for traction. If my rear tires had fluid in them it would raise my center of gravity at the angles I work at. Besides now I can use the three point hitch to lift my rear tires off the ground. With fluid that would be more difficult.