My Champ has a toal of 39 gallons of fuel, granted I have a thirstier engine (O-235), but there have been many time I have filled all the tanks and flown most of the day. I can always set down to "drain my vain" but am not always able to get fuel.....especially in the boonies on the weekends. The ability to find fuel on floats is also a consideration. Last fall I took a flight that was over 6 hours. Got home with fuel to spare. Butt was sore...but I still had fuel!! Just something more to think about.....get the bigger tanks.
WW