I feel a bit better now, sounds like we're pretty close to even.
Which is impressive considering you're missing some panels and such.
On flat level ground, doing 55-65 (prob. average ~63) and with careful driving I managed 77 over a 700 mile tank. It'd be nice if I had a large downhill area to rack up huge numbers like that. Coming down from Nevada into Cali near 80 I managed over 40 in my sister's Avalon, but I was basically just idling down the mountain roads. I don't think Toyota's automatic transmissions do engine braking.