I have a 20113 LSV. We fill the side we surf on 100%, and the front tank to about 70% or so depending on the number of people in the boat (usually 3) The wake plate is in the middle position which in turn gives a very nice wake for surfing. Our speed is 10.4 MPH. My son likes a little faster, 10.8.

One more thing most don't think about is the weight of the fuel tank. Mine is usually near full.