For most CUT owners, filling the front tires is not going to give you a lot of weight since the tires are so small. Some mfg. say not to fill front tires especially if you have a FEL as that load must already stress the axles due to underdesign. Most Ag type tractors have all tires filled since they need all the weight they can get for pulling soil engagement implements. If properly filled, you wont see any difference in handling or steering. You may see a little more lift capacity on the rear end, but I cant imagine how 100 or so pounds is going to help much.. There are tire capacity charts available all over the internet that you can consult to see just how much water each tire size will hold. Consult those and then determine if what you will get will be worth while. I cant believe that adding water to a tire would void a warranty as some have mentioned on TBN or cause excess wear on bearings especially given that the bearing are only carrying the load of what is above centerline of the tire (75% fill= 1/4 weight capacity on the wheel axle) IMO, IF you want to fill, go ahead, I would not worry about damage to the machine.