I have three gas planes in the very near future. I am working on two of them right now, and will receive the third in mid December.
I have a 3W24 in a 1.20 size Sukhoi 31M, it should come out at around 11-12 lbs. I figure an 8-10 oz tank will be enough for 10-15 min. flights.
I also have a zdz80 in a 30%Cap231EX, should come out at 21 lbs. I figure a 24 oz tank should be good for 10-15 min. flights.
Finally I have a zdz40 for which I'll receive a DiablotinXL in a few weeks. I don't know if this plane come with a tank, but if not, I guess a 16 oz tank should be fine for 10-15 min. flights.
Please let me know if I plan to carry to little/much fuel for my planned 10-15 min. flights.
DKjens