Assuming you have Ag tires, you can flip them (actually, swap sides to keep the tread correct). I'm not sure how much you will gain, since I can't get out and look at my TC33 tonight, but it does make a difference. Most people I know leave them set wide, unless they have space concerns like driving through tight trails in the woods. You can get an estimate of how much further out they'll go by looking at how offset the hub of the wheel is from the centerline of the tire (while you are looking, you can make sure yours are not already set to the wider position).
John
NOTE: if you have filled rear tires, swapping them is not something to be taken on without the right equipment. They are heavy and unwieldly. Use caution if you are doing it yourself.
