Tires To load tires or leave them unloaded

[TC18guy]

I'd load the rears. If not for FEL work you'll apreciate it for general stability and traction. I have loaded turfs and primarilly use the tractor for mowing and snow plowing. I also put the rake on the back for doing heavy FEL work.

 

[JTC]

A lot will depend on your soil type. I have loose sandy soil and where I have to repeatedly drive over the same areas while mowing show noticeable tire depressions. This happens mainly around the perimeter of the my lawn so after driving over the same areas, the weight just causes the soil to compact, migrate and form tire depressions over time. That's why I like to be as light as possible when mowing. It only takes about a minute to put on the ballast box.

Jim

 

[3RRL]

I'd load the tires with ballast for general stability. It makes a diferrence on how much you put in depending on what your tractor needs to minimize slippage. Also whether you have 4WD or 2WD and what kind of implements you have hanging off the tractor.
Generally, it makes sense to add the weight as low as possible to keep the center of gravity low. Hanging wieght on the tractor always puts more load on the axles and bearings because the tractor and implements all sit on top of the axles. Adding to the tires does not increase the weight on the axles in the same fashion as hanging weights do. Unfortunately, you may not be able to put enough weight into the tires to accomplish enough "counter balance" for loader work or 3pt work. That's why they make weights to hang on the tractor.
Here's a helpful link that is informative:
http://muextension.missouri.edu/xplor/agguides/agengin/g01235.htm
Hope this helps a little.