B9 Procedural Wing tanks have no dry mass

[talchas]

They have only the wing mass that exists whether or not there is a tank, rather than the various procedural tanks which have a variety of extra dry mass cost. For conventional structure even the top end unpressurized tanks have worse (~10x) dry mass than a 1x1x1 cube with minimum strength, and pressurized tanks are even worse since the wing's tank mass is still 0 (if it can fit your fuels, since the tanks available are more limited). Even with a reasonable strength number they're competitive with the top end conventional tanks if you don't need them to be in a fairing or already have one. For extra silliness they're also cheaper and don't take tooling in RP-1.

For rockets it's easy enough to just ignore it and not use them, but when making rocket planes it would be nice to have less cheesy numbers when using them.