My rear tires were filled too full from the dealer. With the wheel in the air (jacked up) liquid would come out the shrader valve so I removed it, let the liquid out, then added air to the recommended pressure. However I still wonder if lowering the liquid lower would help lower my center of gravity. Wouldn't it benefit if the liquid was down to axle level? I do have a rear ballast box (only 2/3's full to keep it low), so I don't think I need all that tire ballast. But again the question is, would it be more stable with only half way tire ballast, for when I'm mowing without the rear ballast box.