All the big ones are far less dense than the small ones.
10k tank: 3x3, so it's 1.11k per tile. Costs 5 duralumin. Notable for having inputs on only two sides.
15k tank: 3x3. 1.66k per tile. 20 duralumin.
30k tank: 2x2. 7.5k per tile! 15 duralumin. That's the best per tile right now, though it only has inputs on two sides.
40k tank: 3x3. 4.44k per tile. 0 duralumin but far more lead and iron cost than the 30k.
50k tank: 5x5. 2k per tile. 20 duralumin.
65k tank: 5x5. 2.6k per tile.
70k tank: 7x3. 3.33k per tile. 40 duralumin. Notable for being long.
80k tank: 6x6. 2.22k per tile. Even dimensions, with two outputs in the middle of each side.
90k tank: 7x7. 1.84k per tile. 35 duralumin. Two outputs per side again.
100k tank: 8x8. 1.56k per tile. 20 duralumin. Two outputs per side spaced out even more.

Considering these stats and how expensive the big ones are, most of these just aren't worth making. It's better to put down groups of 30k or 40k tanks. IMO the biggest ones should be higher density instead of less, since they're generally taller. Unfortunately the capacities are part of the graphics for some reason so they'd have to be re-rendered... actually, the capacities are wrong on the tanks. They're missing a digit! The 100k tank has 10000 written on it, that's 10k. Similar problem with the rest.